NGG / National Grid plc - Depositary Receipt (Common Stock) - Pemfailan SEC, Laporan Tahunan, Penyata Proksi

National Grid plc - Depositary Receipt (Common Stock)
US ˙ NYSE ˙ US6362744095

Statistik Asas
LEI 8R95QZMKZLJX5Q2XR704
CIK 1004315
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to National Grid plc - Depositary Receipt (Common Stock)
SEC Filings (Chronological Order)
Halaman ini menyediakan senarai kronologi lengkap bagi Pemfailan SEC, tidak termasuk pemfailan pemilikan yang kami sediakan di tempat lain.
August 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 August 2025 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 August 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

August 27, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 27 August 2025 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 27 August 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

August 14, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 August 2025 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 August 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

July 31, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 17, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 17 July 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 17 July 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 16, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 16 July 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 16 July 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 9, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 09 July 2025 Commission File Number: 001-14958

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 09 July 2025 Commission File Number: 001-14958 cc NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

July 1, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 July 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 July 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 30, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 June 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 June 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 13, 2025 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

11-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from       to       Commission File Number 1-14958 National Grid USA Companies’ Incentive Thrift

June 13, 2025 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.2 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement Nos. 333-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 13, 2025, relating to the financial statements and supplemental schedule of the National Grid USA Companies’ Incentive Thrift Plan appearing in this Annual Report on Form 11-K of t

June 13, 2025 EX-99.1

NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2024 AND 2023, AND FOR THE YEAR ENDED DECEMBER 31, 2024, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2024

Exhibit 99.1 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2024 AND 2023, AND FOR THE YEAR ENDED DECEMBER 31, 2024, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2024 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN TABLE OF CONTENTS AS OF DECEMBER 31, 2024 AND 2023, AND FOR THE YEAR ENDED DECEMBER 31, 2024 REPORT OF INDEPENDENT REGISTER

June 5, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 05 June 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 05 June 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 4, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 04 June 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 04 June 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 2, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 30, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 30, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 29, 2025 EX-13.1

RULE 13a-14(b) CERTIFICATION

Exhibit 13.1 RULE 13a-14(b) CERTIFICATION Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18 of the United States Code ) each of the undersigned officers of National Grid plc, a public limited company incorporated under the laws of England and Wales (the “Company”), hereby certifies to such officer’s knowledge, that: The Annua

May 29, 2025 EX-15.1

EX-15.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No.

May 29, 2025 EX-12.1

RULE 13a-14(a) CERTIFICATION

Exhibit 12.1 RULE 13a-14(a) CERTIFICATION I, John Pettigrew, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading w

May 29, 2025 EX-12.2

RULE 13a-14(a) CERTIFICATION

Exhibit 12.2 RULE 13a-14(a) CERTIFICATION I, Andrew Agg, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with

May 29, 2025 EX-11.(B)

INTERNAL USE ONLY The National Grid plc – Share Dealing Policy sets out the rules on dealing in National Grid plc securities for the Board, Senior Management and certain other employees of the Company and its subsidiaries both in the UK and US who ar

INTERNAL USE ONLY The National Grid plc – Share Dealing Policy sets out the rules on dealing in National Grid plc securities for the Board, Senior Management and certain other employees of the Company and its subsidiaries both in the UK and US who are restricted in a number of ways.

May 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 29, 2025 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F (Mark One) £ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR R ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended 31 March 2025 OR £ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

May 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 May 2025 Commission File Number: 001-14958 NATIONAL

6-K 1 a6636k.htm PUBLICATION OF ANNUAL REPORT AND ACCOUNTS & AGM UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdict

May 28, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 27 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 27 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 22, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 22 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 22 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 1, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 May 2025 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 May 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

April 30, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K s REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 April 2025 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K s REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 April 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

April 28, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 April 2025 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 April 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

April 10, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 April 2025 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 April 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

March 31, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 March 2025 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 March 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

March 26, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 25 March 2025 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 25 March 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

February 28, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 February 2025 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 February 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

February 24, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 24 February 2025 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 24 February 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

January 31, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2025 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 14, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 January 2025 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 January 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 13, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 January 2025 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 January 2025 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

December 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 December 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 December 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

December 18, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 December 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 December 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 29, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 29, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 29, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 26, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 25, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 25 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 25 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 18, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 7, 2024 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 7 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 7 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Name) 1-3 Strand London WC2N 5EH, England (Registrant’s Address) Indicate by check mark whether the registrant files or will file annual reports und

November 7, 2024 EX-99.1

Before exceptional items and remeasurements

London | 7 November 2024: National Grid, a leading energy transmission and distribution company, today announces its Half-Year results for the period ended 30 September 2024.

November 7, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 07 November 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 07 November 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

October 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 October 2024 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 October 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

October 3, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 03 October 2024 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 03 October 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

October 2, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 October 2024 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 01 October 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

September 30, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 September 2024 Commission File Number: 001-14958 NAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 September 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

September 26, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 September 2024 Commission File Number: 001-14958 NAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 September 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

September 13, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 September 2024 Commission File Number: 001-14958 NAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 September 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

August 30, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 August 2024 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 August 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

August 28, 2024 EX-25.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE ☐ CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) THE BANK OF NEW YORK MELLON (Exact name of trustee as specified in its charter) New York 13-5160382 (Ju

August 28, 2024 EX-FILING FEES

Calculation of Filing Fee Tables Form F-3 (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables Form F-3 (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security  Type  Security  Class Title  Fee  Calculation  or Carry  Forward  Rule  Amount  Registered  Proposed  Maximum  Offering  Price Per  Unit  Maximum  Aggregate  Offering  Price    Fee      Rate    Am

August 28, 2024 F-3ASR

As filed with the Securities and Exchange Commission on August 28, 2024

Table of Contents As filed with the Securities and Exchange Commission on August 28, 2024 Registration No.

August 28, 2024 EX-1.1

[Form of Underwriting Agreement] UNDERWRITING AGREEMENT National Grid plc $____________% Notes due 20______

Exhibit 1.1 [Form of Underwriting Agreement] UNDERWRITING AGREEMENT National Grid plc $% Notes due 20 , 20 [Name(s) of Representative(s)] As representatives of the several underwriters listed in Schedule 1 hereto Ladies and Gentlemen: National Grid plc, a public limited company incorporated under the laws of England and Wales (the “Company”), proposes to issue and sell to the several underwriters

July 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 26, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 19, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 18, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 18, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 10, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 July 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 July 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 28, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 28, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 26, 2024 11-K/A

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K/A

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K/A ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from     to       Commission File Number 1-14958 National Grid USA Companies’ Incentive Thrift Plan

June 26, 2024 EX-99.1

NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2023

Exhibit 99.1 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2023 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN TABLE OF CONTENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023 REPORT OF INDEPENDENT REGISTER

June 26, 2024 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.2 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement Nos. 333-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 25, 2024, relating to the financial statements and supplemental schedule of the National Grid USA Companies’ Incentive Thrift Plan appearing in this Annual Report on Form 11-K of t

June 25, 2024 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.2 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement Nos. 333-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 25, 2024, relating to the financial statements and supplemental schedule of the National Grid USA Companies’ Incentive Thrift Plan appearing in this Annual Report on Form 11-K of t

June 25, 2024 EX-99.1

NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2023

Exhibit 99.1 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2023 Unaudited – No Assurance Given NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN TABLE OF CONTENTS AS OF DECEMBER 31, 2023 AND 2022, AND FOR THE YEAR ENDED DECEMBER 31, 2023

June 25, 2024 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from     to       Commission File Number 1-14958 National Grid USA Companies’ Incentive Thrift Plan N

June 13, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 12, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 12, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 11, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 June 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 5, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 5 June 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 23, 2024 EX-4.(C)6

1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 11 December 2023 Jacqui Ferguson c/o Grand Buildings 1-3 Strand London, WC2N 5EH United K

1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 11 December 2023 Jacqui Ferguson c/o Grand Buildings 1-3 Strand London, WC2N 5EH United Kingdom Dear Jacqui Appointment as Non-executive Director Further to the approval by the Board of National Grid plc (the “Company”), and subject to agr

May 23, 2024 EX-4.(B)2

Table of Contents

Exhibit 4(b).2 REDACTED VERSION Certain identified information has been omitted from this document because it is not material and is customarily and actually treated as private or confidential, and has been marked with “[***]” to indicate where omissions have been made. Remaining Acquisition Agreement relating to the acquisition of shares in GasT TopCo Dated 19 July 2023 Lattice Group Limited and

May 23, 2024 EX-11.(B)

INTERNAL USE ONLY The National Grid plc – Share Dealing Policy sets out the rules on dealing in National Grid plc securities for the Board, Senior Management and certain other employees of the Company and its subsidiaries both in the UK and US who ar

INTERNAL USE ONLY The National Grid plc – Share Dealing Policy sets out the rules on dealing in National Grid plc securities for the Board, Senior Management and certain other employees of the Company and its subsidiaries both in the UK and US who are restricted in a number of ways.

May 23, 2024 EX-97.1

Final/Linklaters LLP/06/11/2023 A52293244 1 National Grid plc US Clawback Policy 1 DEFINITIONS In this Policy: "ADSs” means American Depositary Shares, each representing five Ordinary Shares; “Applicable Law” means any laws, regulations or rules of t

Final/Linklaters LLP/06/11/2023 A52293244 1 National Grid plc US Clawback Policy 1 DEFINITIONS In this Policy: "ADSs” means American Depositary Shares, each representing five Ordinary Shares; “Applicable Law” means any laws, regulations or rules of the US Securities and Exchange Commission, the NYSE, the London Stock Exchange, any other stock exchange on which the Company’s securities are listed o

May 23, 2024 EX-2.(B)19

11/81536398_4 1 __ AUGUST 2023 NATIONAL GRID ELECTRICITY DISTRIBUTION (EAST MIDLANDS) PLC NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WALES) PLC NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WEST) PLC and NATIONAL GRID ELECTRICITY DISTRIBUTION (WES

11/815363984 1 AUGUST 2023 NATIONAL GRID ELECTRICITY DISTRIBUTION (EAST MIDLANDS) PLC NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WALES) PLC NATIONAL GRID ELECTRICITY DISTRIBUTION (SOUTH WEST) PLC and NATIONAL GRID ELECTRICITY DISTRIBUTION (WEST MIDLANDS) PLC (as Issuers) HSBC CORPORATE TRUSTEE COMPANY (UK) LIMITED (as Trustee) AMENDED AND RESTATED TRUST DEED related to the £6,000,000,000 Euro Medium Term Note Programme of the Issuers Herbert Smith Freehills EXECUTION VERSION 10 11/815363984 1 CONTENTS Clause Page 1.

May 23, 2024 EX-12.2

RULE 13a-14(a) CERTIFICATION

Exhibit 12.2 RULE 13a-14(a) CERTIFICATION I, Andrew Agg, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with

May 23, 2024 EX-12.1

RULE 13a-14(a) CERTIFICATION

Exhibit 12.1 RULE 13a-14(a) CERTIFICATION I, John Pettigrew, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading w

May 23, 2024 EX-17.1

1

Exhibit 17.1 Subsidiary Guarantors and Issuers of Guaranteed Securities Each of the following securities issued by Niagara Mohawk Power Corporation, a wholly owned subsidiary of the Group, is unconditionally and fully guaranteed by National Grid plc: •3.60% preferred shares •3.90% preferred shares / / 1

May 23, 2024 EX-15.1

EX-15.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No.

May 23, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 May 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 23, 2024 EX-4.(B)1

Table of Contents

Exhibit 4(b).1 REDACTED VERSION Certain identified information has been omitted from this document because it is not material and is customarily and actually treated as private or confidential, and has been marked with “[***]” to indicate where omissions have been made. Amended and Restated Further Acquisition Agreement relating to the acquisition of shares in GasT TopCo Dated 19 July 2023 Lattice

May 23, 2024 EX-13.1

RULE 13a-14(b) CERTIFICATION

Exhibit 13.1 RULE 13a-14(b) CERTIFICATION Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18 of the United States Code ) each of the undersigned officers of National Grid plc, a public limited company incorporated under the laws of England and Wales (the “Company”), hereby certifies to such officer’s knowledge, that: The Annua

May 23, 2024 EX-2.(C)

DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE EXCHANGE ACT

Exhibit 2(c) DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE EXCHANGE ACT As of 31 March 2024, National Grid plc (the Company, National Grid, we, us, and our) had the following securities registered pursuant to Section 12(b) of the Securities Exchange Act of 1934 (the Exchange Act): Title of Each Class Trading Symbol Name of Each Exchange on Which Registered Ordinary Shares of 12 204/473 pence each American Depositary Shares, each representing five Ordinary Shares NG NGG New York Stock Exchange* New York Stock Exchange 5.

May 23, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 May 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 May 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 23, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 May 2024 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 May 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 23, 2024 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F (Mark One) £ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR R ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended 31 March 2024 OR £ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

May 23, 2024 EX-2.(B)18

EXECUTION VERSION Amended and Restated Trust Deed relating to National Grid North America Inc.’s Euro 8,000,000,000 Euro Medium Term Note Programme arranged by HSBC Bank plc Dated 4 August 2023 NATIONAL GRID NORTH AMERICA INC. as Issuer and THE LAW D

EXECUTION VERSION Amended and Restated Trust Deed relating to National Grid North America Inc.

May 23, 2024 EX-4.(A)1

Exhibit 4(a).1 REDACTED VERSION FOR INFORMATION ONLY The securities offered pursuant to the rights issue have not been and will not be registered under the United States Securities Act of 1933 and may not be offered or sold in the United States unles

exhibit4a1-underwritinga Exhibit 4(a).1 REDACTED VERSION FOR INFORMATION ONLY The securities offered pursuant to the rights issue have not been and will not be registered under the United States Securities Act of 1933 and may not be offered or sold in the United States unless in a transaction that is registered thereunder or exempt from the registration requirements thereof. No public offer has be

April 30, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 April 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 April 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

April 18, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 April 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 April 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

April 10, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 April 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 April 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

March 28, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 March 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 March 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

March 11, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 March 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 March 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

March 7, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 07 March 2024 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 07 March 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

February 29, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 February 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 February 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

February 8, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 08 February 2024 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 08 February 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

January 31, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2024 Commission File Number: 001-14958 NATIO

CORPORATE UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH,

January 17, 2024 8-A12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 National Grid plc (Exact Name of Registrant a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 National Grid plc (Exact Name of Registrant as Specified in Its Charter) England and Wales 98-0367158 (Jurisdiction of Incorporation or Organization) (I.R.S. Employer Identification No.) 1-3 Stra

January 11, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 January 2024 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 January 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 11, 2024 EX-1.1

UNDERWRITING AGREEMENT National Grid plc $750,000,000 5.418% Notes due 2034

Exhibit 1.1 UNDERWRITING AGREEMENT National Grid plc $750,000,000 5.418% Notes due 2034 January 8, 2024 BNP Paribas Securities Corp. 787 Seventh Avenue New York, NY 10019 United States of America Citigroup Global Markets Inc. 388 Greenwich Street New York, NY 10013 United States of America Mizuho Securities USA LLC 1271 Avenue of the Americas New York, NY 10020 United States of America Morgan Stan

January 11, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2024 Commission File Number: 001-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January, 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) 1-3 Strand London WC2N 5EH, England (Address of principal executive office) Ind

January 11, 2024 EX-4.1

SECOND SUPPLEMENTAL INDENTURE by and between NATIONAL GRID PLC, the Company THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee and Paying Agent relating to an Indenture, dated as of June 12, 2023 January 11, 2024

Exhibit 4.1 SECOND SUPPLEMENTAL INDENTURE by and between NATIONAL GRID PLC, the Company and THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee and Paying Agent relating to an Indenture, dated as of June 12, 2023 January 11, 2024 Table of Contents Contents Page ARTICLE 1 Definitions and Other Provisions of General Application 1 SECTION 1.1 Definitions 1 SECTION 1.2 Conflict with Trust Indenture

January 10, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 January 2024 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 January 2024 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 9, 2024 EX-FILING FEES

Calculation of Filing Fee Tables (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Tables 424(b)(5) (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Debt U.

January 9, 2024 424B5

National Grid plc U.S.$750,000,000 5.418% Notes due 2034

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-256888 Prospectus Supplement (To Base Prospectus dated June 8, 2021) National Grid plc U.S.$750,000,000 5.418% Notes due 2034 The U.S.$750,000,000 notes due 2034 (the “Notes”) will bear interest at 5.418% per year. Interest on the Notes will be payable semi-annually in arrears on January 11 and July 11 of each year, beginning

January 8, 2024 FWP

National Grid plc U.S.$750,000,000 5.418% Notes due 2034 Pricing Term Sheet Issuer: National Grid plc Type: SEC-registered Ratings*: Baa2 (Moody’s) / BBB (S&P) / BBB (Fitch) Size: $750,000,000 Maturity: January 11, 2034 Coupon: 5.418% Price: 100% of

Filed Pursuant to Rule 433 Registration Statement No. 333-256888 Dated: January 8, 2024 Pricing Term Sheet National Grid plc U.S.$750,000,000 5.418% Notes due 2034 Pricing Term Sheet Issuer: National Grid plc Type: SEC-registered Ratings*: Baa2 (Moody’s) / BBB (S&P) / BBB (Fitch) Size: $750,000,000 Maturity: January 11, 2034 Coupon: 5.418% Price: 100% of face amount Yield to maturity: 5.418% Sprea

January 8, 2024 424B5

SUBJECT TO COMPLETION, DATED JANUARY 8, 2024

Table of Contents The information in this preliminary prospectus supplement is not complete and may be changed.

January 3, 2024 15-12G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-02987 Niagara Mohawk Power Corporation (as issuer of the 3.60% Preferred St

January 2, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 December 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 December 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

December 21, 2023 25

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 25 NOTIFICATION OF REMOVAL FROM LISTING AND/OR REGISTRATION UNDER SECTION 12(b) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-02987 Niagara Mohawk Power Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 25 NOTIFICATION OF REMOVAL FROM LISTING AND/OR REGISTRATION UNDER SECTION 12(b) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-02987 Niagara Mohawk Power Corporation (as issuer of the 3.60% Preferred Stock and the 3.90% Preferred Stock) National Grid plc (as guarantor of the 3.60% Preferred Stock and the

December 13, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 December 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 13 December 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

December 11, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 December 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 December 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 30, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 November 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 30, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 November 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 24, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 November 2023 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 23 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

November 9, 2023 EX-99.1

Before exceptional items and remeasurements

London | 9 November 2023: National Grid, a leading energy transmission and distribution company, today announces its Half-Year results for the period ended 30 September 2023.

November 9, 2023 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 9 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 9 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

November 9, 2023 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 9 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 9 November 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Name) 1-3 Strand London WC2N 5EH, England (Registrant’s Address) Indicate by check mark whether the registrant files or will file annual reports und

October 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 October 2023 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 October 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

October 5, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 5 October 2023 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 5 October 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

September 29, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 September 2023 Commission File Number: 001-14958 NAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 September 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

August 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 August 2023 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 August 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

August 9, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 09 August 2023 Commission File Number: 001-14958 NATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 09 August 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kin

August 8, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 8 August 2023 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 8 August 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

July 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 July 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 19, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 July 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 July 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 10, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 July 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 July 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

July 7, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 06 July 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 06 July 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 30, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 June 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 June 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingd

June 23, 2023 EX-99.1

NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2022 AND 2021, AND FOR THE YEAR ENDED DECEMBER 31, 2022, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2022

EX-99.1 Exhibit 99.1 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN FINANCIAL STATEMENTS AS OF DECEMBER 31, 2022 AND 2021, AND FOR THE YEAR ENDED DECEMBER 31, 2022, AND ERISA-REQUIRED SUPPLEMENTAL SCHEDULE AS OF DECEMBER 31, 2022 NATIONAL GRID USA COMPANIES’ INCENTIVE THRIFT PLAN TABLE OF CONTENTS AS OF DECEMBER 31, 2022 AND 2021, AND FOR THE YEAR ENDED DECEMBER 31, 2022 REPORT OF INDEPENDENT

June 23, 2023 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

EX-99.2 Exhibit 99.2 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement Nos. 333-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 23, 2023, relating to the financial statements and supplemental schedule of the National Grid USA Companies’ Incentive Thrift Plan appearing in this Annual Report on Form 1

June 23, 2023 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

11-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K ☑ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-14958 National Grid USA Companies’ Incentive Thrift Plan Nation

June 15, 2023 8-A12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 National Grid plc (Exact Name of Registrant a

8-A12B UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 National Grid plc (Exact Name of Registrant as Specified in Its Charter) England and Wales 98-0367158 (Jurisdiction of Incorporation or Organization) (I.R.S. Employer Identification No.) 1

June 12, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June, 2023 Commission File Number: 001-1495

Form 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June, 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) 1-3 Strand London WC2N 5EH, England (Address of principal executive offic

June 12, 2023 EX-4.1

Indenture Dated June 12, 2023 by and between NATIONAL GRID PLC, the Company THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee

EX-4.1 Exhibit 4.1 Indenture Dated June 12, 2023 by and between NATIONAL GRID PLC, the Company and THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee TABLE OF CONTENTS Contents Page ARTICLE I DEFINITIONS 3 Section 1.1 Certain Terms Defined 3 ARTICLE II SECURITY FORMS 10 Section 2.1 Forms Generally 10 Section 2.2 Form of Trustee’s Certificate of Authentication 11 Section 2.3 Securities Issuable

June 12, 2023 EX-1.1

UNDERWRITING AGREEMENT National Grid plc $700,000,000 5.602% Notes due 2028 $800,000,000 5.809% Notes due 2033

EX-1.1 Exhibit 1.1 UNDERWRITING AGREEMENT National Grid plc $700,000,000 5.602% Notes due 2028 $800,000,000 5.809% Notes due 2033 June 7, 2023 BofA Securities, Inc. One Bryant Park New York, NY 10036 United States of America Goldman Sachs & Co. LLC 200 West Street New York, NY 10282 United States of America Mizuho Securities USA LLC 1271 Avenue of the Americas New York, NY 10020 United States of A

June 12, 2023 EX-4.2

FIRST SUPPLEMENTAL INDENTURE by and between NATIONAL GRID PLC, the Company THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee and Paying Agent relating to an Indenture, dated as of June 12, 2023 June 12, 2023

EX-4.2 Exhibit 4.2 FIRST SUPPLEMENTAL INDENTURE by and between NATIONAL GRID PLC, the Company and THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee and Paying Agent relating to an Indenture, dated as of June 12, 2023 June 12, 2023 Table of Contents Contents Page ARTICLE 1 Definitions and Other Provisions of General Application 1 SECTION 1.1 Definitions 1 SECTION 1.2 Conflict with Trust Indent

June 8, 2023 FWP

National Grid plc U.S.$700,000,000 5.602% Notes due 2028 Pricing Term Sheet Issuer: National Grid plc Type: SEC-registered Ratings*: Baa2 (Moody’s) / BBB (S&P) / BBB (Fitch) Size: $700,000,000 Maturity: June 12, 2028 Coupon: 5.602% Price: 100% of fac

FWP Filed Pursuant to Rule 433 Registration Statement No. 333-256888 Dated: June 7, 2023 Pricing Term Sheet National Grid plc U.S.$700,000,000 5.602% Notes due 2028 Pricing Term Sheet Issuer: National Grid plc Type: SEC-registered Ratings*: Baa2 (Moody’s) / BBB (S&P) / BBB (Fitch) Size: $700,000,000 Maturity: June 12, 2028 Coupon: 5.602% Price: 100% of face amount Yield to maturity: 5.602% Spread

June 8, 2023 424B5

National Grid plc U.S.$700,000,000 5.602% Notes due 2028 U.S.$800,000,000 5.809% Notes due 2033

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-256888 Prospectus Supplement (To Base Prospectus dated June 8, 2021) National Grid plc U.S.$700,000,000 5.602% Notes due 2028 U.S.$800,000,000 5.809% Notes due 2033 The U.S.$700,000,000 notes due 2028 (the “ 2028 Notes”) will bear interest at 5.602% per year. Interest on the 2028 Notes will be payable semi-annually in ar

June 8, 2023 EX-FILING FEES

Calculation of Filing Fee Tables (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Prop

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables 424(b)(5) (Form Type) National Grid plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Debt U.

June 6, 2023 EX-4.(C)17

1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 18 May 2022 Iain Mackay 980 Great West Road, Brentford, Middlesex, TW8 9GS United Kingdom

ex4c17iainxmackayx-xapp 1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 18 May 2022 Iain Mackay 980 Great West Road, Brentford, Middlesex, TW8 9GS United Kingdom Appointment as Non-executive Director Further to the approval by the Board of National Grid plc (the “Company”), and subject

June 6, 2023 EX-15.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 15.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No. 333-256888 on Form F-3 and Registration Statement Nos. 333-33094, 333-65968, 333-97249, 333-103768, 333-107727, 333-149828, 333-155527, 333-170716, 333-175852, and 333-184558 on Form S-8 of our reports dated 17 May 2023, relating to the consolidated finan

June 6, 2023 EX-12.2

RULE 13a-14(a) CERTIFICATION

Exhibit 12.2 RULE 13a-14(a) CERTIFICATION I, Andrew Agg, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with

June 6, 2023 EX-2.(C)

DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE EXCHANGE ACT

Exhibit 2(c) DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE EXCHANGE ACT As of 31 March 2023, National Grid plc (the Company, National Grid, we, us, and our) had the following securities registered pursuant to Section 12(b) of the Securities Exchange Act of 1934 (the Exchange Act): Title of Each Class Trading Symbol Name of Each Exchange on Which Registered Ordinary Shares of 12 204/473 pence each American Depositary Shares, each representing five NG NGG The New York Stock Exchange* The New York Stock Exchange Preferred Stock ($100 par value-cumulative) – 3.

June 6, 2023 EX-2.(B)17

11/75893291_6 1 24 AUGUST 2022 WESTERN POWER DISTRIBUTION (EAST MIDLANDS) PLC WESTERN POWER DISTRIBUTION (SOUTH WALES) PLC WESTERN POWER DISTRIBUTION (SOUTH WEST) PLC and WESTERN POWER DISTRIBUTION (WEST MIDLANDS) PLC (as Issuers) HSBC CORPORATE TRUS

ex2b17-trustdeedwpd 11/758932916 1 24 AUGUST 2022 WESTERN POWER DISTRIBUTION (EAST MIDLANDS) PLC WESTERN POWER DISTRIBUTION (SOUTH WALES) PLC WESTERN POWER DISTRIBUTION (SOUTH WEST) PLC and WESTERN POWER DISTRIBUTION (WEST MIDLANDS) PLC (as Issuers) HSBC CORPORATE TRUSTEE COMPANY (UK) LIMITED (as Trustee) AMENDED AND RESTATED TRUST DEED related to the £6,000,000,000 Euro Medium Term Note Programme of the Issuers Herbert Smith Freehills EXECUTION VERSION 11/758932916 1 CONTENTS Clause Page 1.

June 6, 2023 424B5

SUBJECT TO COMPLETION, DATED June 6, 2023

424B5 Table of Contents The information in this preliminary prospectus supplement is not complete and may be changed.

June 6, 2023 EX-12.1

RULE 13a-14(a) CERTIFICATION

Exhibit 12.1 RULE 13a-14(a) CERTIFICATION I, John Pettigrew, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading w

June 6, 2023 EX-2.(B)16

EXECUTION VERSION Amended and Restated Trust Deed relating to National Grid plc and National Grid Electricity Transmission plc Euro 20,000,000,000 Euro Medium Term Note Programme arranged by HSBC Bank plc Dated 11 August 2022 NATIONAL GRID PLC and NA

ex2b16-trustdeedngplcnge EXECUTION VERSION Amended and Restated Trust Deed relating to National Grid plc and National Grid Electricity Transmission plc Euro 20,000,000,000 Euro Medium Term Note Programme arranged by HSBC Bank plc Dated 11 August 2022 NATIONAL GRID PLC and NATIONAL GRID ELECTRICITY TRANSMISSION PLC as Issuers and THE LAW DEBENTURE TRUST CORPORATION P.

June 6, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 6 June 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 6 June 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

June 6, 2023 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F (Mark One) £ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR R ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended 31 March 2023 OR £ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

June 6, 2023 EX-13.1

RULE 13a-14(b) CERTIFICATION

Exhibit 13.1 RULE 13a-14(b) CERTIFICATION Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18 of the United States Code ) each of the undersigned officers of National Grid plc, a public limited company incorporated under the laws of England and Wales (the “Company”), hereby certifies to such officer’s knowledge, that: The Annua

June 5, 2023 EX-25.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

EX-25.1 Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE ☐ CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) THE BANK OF NEW YORK MELLON (Exact name of trustee as specified in its charter) New York 13-516

June 5, 2023 EX-4.1

Indenture Dated [•] 2023 by and between NATIONAL GRID PLC, the Company THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee

EX-4.1 Exhibit 4.1 Indenture Dated [•] 2023 by and between NATIONAL GRID PLC, the Company and THE BANK OF NEW YORK MELLON, LONDON BRANCH, as Trustee TABLE OF CONTENTS Contents Page ARTICLE I DEFINITIONS 2 Section 1.1 Certain Terms Defined 2 ARTICLE II SECURITY FORMS 9 Section 2.1 Forms Generally 9 Section 2.2 Form of Trustee’s Certificate of Authentication 10 Section 2.3 Securities Issuable in the

June 5, 2023 POSASR

As filed with the Securities and Exchange Commission on June 5, 2023

POSASR As filed with the Securities and Exchange Commission on June 5, 2023 Registration No.

May 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 May 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

May 18, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 May 2023 Commission File Number: 001-14958 NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 18 May 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Kingdo

April 28, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 April 2023 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28 April 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

April 3, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 March 2023 Commission File Number: 001-14958 NATIONA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 March 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United King

February 28, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28th February 2023 Commission File Number: 001-14958 NA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 28th February 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

February 9, 2023 SC 13G/A

NMK.PRC / Niagara Mohawk Power Corp. / BAIRD ROBERT W & CO INC /WI/ - AMENDED SCHEDULE FILED TO REPORT ACQUISITION OF BENEFICIAL OWNERSHIP 12-31-22 Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Niagara Mohawk Power Corporation (Name of Issuer) 3.90% Series Preferred Stock (Title of Class of Securities) 653522409 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the r

January 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2023 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 31, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2023 Commission File Number: 001-14958 NATIO

6-K 1 a4297o.htm SALE COMPLETION:MAJORITY INTEREST, NGGT & METERING UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 31 January 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Ju

January 11, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 January 2023 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 January 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

January 10, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 January 2023 Commission File Number: 001-14958 NATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 January 2023 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United Ki

December 30, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 December 2022 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30 December 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

December 15, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 December 2022 Commission File Number: 001-14958 NATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 15 December 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant?s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United K

December 14, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14th December 2022 Commission File Number: 001-14958 NA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 14th December 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant?s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

December 5, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 05th December 2022 Commission File Number: 001-14958 NA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 05th December 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant?s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

December 1, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 1st December 2022 Commission File Number: 001-14958 NAT

6-K 1 a2861i.htm SCRIP DIVIDEND FOR 2022/23 INTERIM DIVIDEND UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 1st December 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant’s name into English) England and Wales (Jurisdi

November 30, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30th November 2022 Commission File Number: 001-14958 NA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Date: 30th November 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Translation of registrant?s name into English) England and Wales (Jurisdiction of Incorporation) 1-3 Strand, London, WC2N 5EH, United

November 10, 2022 EX-99.1

Financial Summary Six months ended 30 September: continuing operations1 Statutory results Underlying2 Unaudited 2022 2021 % change 2022 2021 % change Operating profit (£m) 2,239 1,492 50 % 2,117 1,407 50 % Profit before tax (£m) 1,572 1,083 45 % 1,45

Exhibit 99.1 National Grid 2022/23 Half Year Results Statement London | 10 November 2022: National Grid, a leading energy transmission and distribution company, today announces its Half-Year results. Report for the period ended 30 September 2022 John Pettigrew Chief Executive ?The results we?ve announced today reflect the strength and resilience of our business, delivering for all our stakeholders

November 10, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 November 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 November 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports un

November 10, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 November 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 November 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports un

November 10, 2022 EX-99.1

Before exceptional items and remeasurements

London | 10 November 2022: National Grid, a leading energy transmission and distribution company, today announces its Half-Year results.

October 12, 2022 EX-99.1

National Grid plc Pre-Close Update ahead of 2022/23 Half Year Results

Exhibit 99.1 10 October 2022 National Grid plc Pre-Close Update ahead of 2022/23 Half Year Results National Grid today issues a pre-close update in respect of the half year ending 30 September 2022. Overall, the group continues to perform in line with our expectations and remains focused on delivering the clean energy transition. Half year results will be announced on 10 November 2022. These resul

October 12, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 October 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 12 October 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports und

October 6, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Re

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual re

October 6, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 6 October 2022 4 October 2022 Director/PDMR Shareho

October 6, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 6 October 2022 4 October 2022 National Grid p

September 6, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 6 September 2022 2 September 2022 National Gr

September 6, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 6 September 2022 2 September 2022 Director/PDMR Sha

September 6, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual

August 17, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 17 August 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 17 August 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports unde

August 17, 2022 EX-99.1

National Grid plc (‘National Grid’ or ‘Company’) Voting Rights and Capital update

Exhibit 99.1 17 August 2022 National Grid plc (?National Grid? or ?Company?) Voting Rights and Capital update National Grid confirms that, following the issue of 10,284,667 ordinary shares earlier today, in relation to the operation of the Scrip Dividend Scheme for the 2021/22 final dividend, National Grid's registered capital consists of 3,914,359,015 ordinary shares, of which 254,291,405 shares

August 16, 2022 EX-99.1

National Grid plc (‘National Grid’ or ‘Company’) National Grid plc Scrip Dividend

Exhibit 99.1 16 August 2022 National Grid plc (?National Grid? or ?Company?) National Grid plc Scrip Dividend National Grid confirms that an application has been made to the Financial Conduct Authority for ordinary shares to be admitted to the Official List, and to the London Stock Exchange for 10,284,667 ordinary shares to be admitted to trading, in relation to the operation of the Scrip Dividend

August 16, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 16 August 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 16 August 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports unde

August 5, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 5 August 2022 3 August 2022 National Grid plc

August 5, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Reg

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual rep

August 5, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 5 August 2022 3 August 2022 Director/PDMR Sharehold

July 11, 2022 EX-99.1

National Grid plc (‘National Grid’ or ‘the Company’) Publication of AGM Results

Exhibit 99.1 11 July 2022 National Grid plc (?National Grid? or ?the Company?) Publication of AGM Results The Company announces that the following resolutions were duly passed at the Company?s 2022 Annual General Meeting (?AGM?) which was held today at 10.00am at Royal Lancaster London, Lancaster Terrace, London W2 2TY. Resolutions 1 to 23 (inclusive) were passed as ordinary resolutions; resolutio

July 11, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 July 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s N

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 11 July 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under

July 8, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Regis

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual repor

July 8, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 8 July 2022 5 July 2022 National Grid plc ('N

July 8, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 8 July 2022 5 July 2022 Director/PDMR Shareholding

June 29, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s N

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 29 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under

June 29, 2022 EX-99.1

National Grid plc RIIO–ED2 price control draft determinations published

Exhibit 99.1 29 June 2022 National Grid plc RIIO?ED2 price control draft determinations published As part of its process for setting new price controls for electricity distribution companies, Ofgem has today published its draft determinations for RIIO?ED2 which will cover UK Electricity Distribution for the period from April 2023 to March 2028. These draft determinations are the next step along th

June 24, 2022 EX-99.1

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.1 National Grid USA Companies? Incentive Thrift Plan Statements of Net Assets Available for Benefits as of December 31, 2021 and 2020 and Statement of Changes in Net Assets Available for Benefits for the Year Ended December 31, 2021 Supplemental Schedule as of December 31, 2021 and Report of Independent Registered Public Accounting Firm Contents Report of Independent Registered Public A

June 24, 2022 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K ? ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-14958 National Grid USA Companies? Incentive Thrift Plan I National

June 24, 2022 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.2 CliftonLarsonAllen LLP CLAconnect.com CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No. 33-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 24, 2022 appearing in this Annual Report on Form 11-K of National Grid USA Companies? Incentive Thrift Plan I for the year ended December 31, 20

June 24, 2022 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K ? ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-14958 National Grid USA Companies? Incentive Thrift Plan National Gr

June 24, 2022 EX-99.1

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.1 National Grid USA Companies? Incentive Thrift Plan I Statements of Net Assets Available for Benefits as of December 31, 2021 and 2020 and Statement of Changes in Net Assets Available for Benefits for the Year Ended December 31, 2021 Report of Independent Registered Public Accounting Firm Contents Report of Independent Registered Public Accounting Firm 1-2 Financial Statements Statemen

June 24, 2022 EX-99.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Exhibit 99.2 CliftonLarsonAllen LLP CLAconnect.com CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No. 333-33094, 333-97249, and 333-149828 on Form S-8 of our report dated June 24, 2022 appearing in this Annual Report on Form 11-K of National Grid USA Companies? Incentive Thrift Plan for the year ended December 31, 202

June 10, 2022 EX-99.1

National Grid plc ('National Grid' or 'Company') Scrip Dividend for 2021/22 Final Dividend

EXHIBIT 99.1 10 June 2022 National Grid plc ('National Grid' or 'Company') Scrip Dividend for 2021/22 Final Dividend The optional scrip dividend, allowing shareholders to receive new fully paid ordinary shares in the Company, instead of a cash dividend, is available to ordinary shareholders on the register on 6 June 2022, the 2021/22 final dividend record date. A timetable is provided below. For o

June 10, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s N

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 10 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under

June 7, 2022 EX-4.(C)18

Letter of Appointment—Lord Ian Livingston

EX-4.(C)18 6 ex4c18lordianxlivingsto.htm EX-4.(C)18 1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 7 July 2021 Lord Ian Livingston 35 Barham Avenue Elstree Herts WD6 3PW Appointment as Non-executive Director Further to the approval by the Board of National Grid plc (the “Company”), and

June 7, 2022 EX-4.(B)1

Acquisition Agreement Lattice Group Limited and Luppiter Bidco Limited dated 22 March 2022 relating to the subscription of shares in GasT TopCo and the acquisition of National Grid Gas Holdings Limited

REDACTED VERSION Certain identified information has been omitted from this document because it is not material and is customarily and actually treated as private or confidential, and has been marked with ?[***]? to indicated where omissions have been made.

June 7, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Regis

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual repor

June 7, 2022 EX-13.1

Certifications of John Pettigrew and Andrew Agg furnished pursuant to Rule 13a-14(b) of the Exchange Act (such certifications are not deemed filed for purpose of Section18 of the Exchange Act and not incorporated by reference in any filing under the Securities Act).

Exhibit 13.1 RULE 13a-14(b) CERTIFICATION Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18 of the United States Code ) each of the undersigned officers of National Grid plc, a public limited company incorporated under the laws of England and Wales (the ?Company?), hereby certifies to such officer?s knowledge, that: The Annua

June 7, 2022 EX-2.(B)14

Amended and Restated Trust Deed dated 16 August 2021 among National Grid plc, National Grid Electricity Transmission plc and the Law Debenture Trust Corporation p.l.c. relating to a €15,000,000,000 Euro Medium Term Note Programme.

Exhibit 2(b).14 Dated 16 August 2021 NATIONAL GRID PLC and NATIONAL GRID ELECTRICITY TRANSMISSION PLC as Issuers EXECUTION VERSION and THE LAW DEBENTURE TRUST CORPORATION P.L.C. as Trustee Ref: L-314979 1 Table of Contents Contents Page 1Interpretation 1 2Issue of Instruments and Covenant to Pay 7 3Form of the Instruments 9 4Stamp Duties and Taxes 10 5Application of Moneys Received by the Trustee

June 7, 2022 EX-2.(B)15

Amended and Restated Trust Deed dated 22 October 2021 between National Grid North America and the Law Debenture Trust Corporation p.l.c. relating to a €8,000,000,000 Euro Medium Term Note Programme

EXECUTION VERSION Amended and Restated Trust Deed relating to National Grid North America Inc.

June 7, 2022 EX-4.(C)21

Letter of Appointment—Martha Wyrsch

1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 20 July 2021 Martha B. Wyrsch 723 Snowmass Club Circle #92 POB 5061 Snowmass Village CO 81615 USA Appointment as Non-executive Director Further to the approval by the Board of National Grid plc (the ?Company?), and subject to agreement of

June 7, 2022 EX-15.1

Consent of Deloitte LLP, independent registered public accounting firm to National Grid plc.

EX-15.1 13 ex-151deloitteconsent.htm EX-15.1 Exhibit 15.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No. 333-256888 on Form F-3 and Registration Statement Nos. 333-33094, 333-65968, 333-97249, 333-103768, 333-107727, 333-149828, 333-155527, 333-170716, 333-175852, and 333-184558 on Form S-8 of our reports dated 18

June 7, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 7 June 2022 6 June 2022 Director/PDMR Shareholding

June 7, 2022 EX-4.(C)20

Letter of Appointment—Tony Wood

1-3 Strand London WC2N 5EH www.nationalgrid.com National Grid plc, Registered Office: 1-3 Strand, London WC2N 5EH. Registered in England and Wales No. 4031152 1 20 July 2021 Tony Wood Lydes Farm Toddington Gloucestershire GL54 5DP Appointment as Non-executive Director Further to the approval by the Board of National Grid plc (the ?Company?), and subject to agreement of these terms and conditions b

June 7, 2022 EX-4.(C)19

Letter of Appointment—Anne Robinson

June 7, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 7 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Na

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 7 June 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under c

June 7, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

EX-99.2 3 ex9926-kannouncments7jun.htm EX-99.2 Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period t

June 7, 2022 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F (Mark One) ? REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR R ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended 31 March 2022 OR `? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

June 7, 2022 EX-12.2

Certification of Andrew Agg pursuant to Rule 13a-14(a) of the Exchange Act

Exhibit 12.2 RULE 13a-14(a) CERTIFICATION I, Andrew Agg, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with

June 7, 2022 EX-1.1

Articles of Association of National Grid plc as amended by Special Resolution passed on 26 July 2021.

Exhibit 1.1 Ref: L-309674 Table of contents Article Page Introduction 1 1Default Articles and other standard regulations do not apply 1 2The meaning of the Articles 1 3Shareholders? Liabilities 5 4Fractions of shares 5 5The power to reduce capital 6 6Buying back shares 6 7The special rights of new shares 6 8The Directors? power to deal with shares 7 9Power to pay commission and brokerage 7 10No tr

June 7, 2022 EX-99.1

National Grid plc ('National Grid' or 'the Company') Publication of Annual Report and Accounts and Notice of 2022 Annual General Meeting

Exhibit 99.1 7 June 2022 National Grid plc ('National Grid' or 'the Company') Publication of Annual Report and Accounts and Notice of 2022 Annual General Meeting In compliance with Listing Rule 9.6.1 and Disclosure Guidance and Transparency Rule (?DTR?) 4.1, National Grid has today published the following documents: ?Annual Report and Accounts 2021/22 ?Annual Report on Form 20-F 2021/22 ?Notice of

June 7, 2022 EX-12.1

Certification of John Pettigrew pursuant to Rule 13a-14(a) of the Exchange Act.

Exhibit 12.1 RULE 13a-14(a) CERTIFICATION I, John Pettigrew, certify that: 1. I have reviewed this annual report on Form 20-F of National Grid plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading w

May 26, 2022 EX-99.1

National Grid plc Completion of sale of The Narragansett Electric Company

EX-99.1 2 ex991necosalecompletion-rn.htm EX-99.1 Exhibit 99.1 25 May 2022 National Grid plc Completion of sale of The Narragansett Electric Company National Grid plc is pleased to announce that it has today completed the sale of The Narragansett Electric Company to PPL Rhode Island Holdings, LLC. Enquiries: National Grid Investors and Analysts Nick Ashworth +44 (0) 7814 355 590 Angela Broad +44 (0

May 26, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Na

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 26 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under c

May 19, 2022 EX-99.1

National Grid 2021/22 Full Year Results Statement 1 A record year of investment to enable the energy transition London | 19 May 2022: National Grid, a leading energy transmission and distribution company, today announces its Full Year results for the

National Grid 2021/22 Full Year Results Statement 1 A record year of investment to enable the energy transition London | 19 May 2022: National Grid, a leading energy transmission and distribution company, today announces its Full Year results for the period ending 31 March 2022.

May 19, 2022 EX-99.1

National Grid plc ('National Grid' or 'the Company') Board Changes

Exhibit 99.1 19 May 2022 National Grid plc ('National Grid' or 'the Company') Board Changes National Grid is pleased to announce the appointment of Iain Mackay as a Non-executive Director of the Board with effect from 11 July 2022, standing for election at the Company?s 2022 Annual General Meeting (AGM). On appointment Iain will be a member of the Audit & Risk Committee and Remuneration Committee.

May 19, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Na

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under c

May 19, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s Na

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 19 May 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under c

May 10, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 10 May 2022 10 May 2022 Director/PDMR Shareholding

May 10, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Regist

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual report

May 10, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

EX-99.2 3 ex9926-kannouncments10ma.htm EX-99.2 Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period t

April 14, 2022 EX-99.1

National Grid plc Pre-Close Update ahead of 2021/22 Full Year Results

EXHIBIT 99.1 14 April 2022 National Grid plc Pre-Close Update ahead of 2021/22 Full Year Results National Grid today issues a pre-close update in respect of the full year ending 31 March 2022. Full year results will be announced on 19 May 2022. We expect underlying operating profit across our New England, New York, and National Grid Ventures (NGV and Other) business units to be in line with the gu

April 14, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 April 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant’s

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date: 14 April 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual reports under

April 12, 2022 EX-99.1

FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, Lon

EXHIBIT 99.1 SUMMARY FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to 12 April 2022 11 April 2022 Director/PDMR Sharehold

April 12, 2022 EX-99.2

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange Nationa

Exhibit 99.2 ANNOUNCEMENTS FORM 6-K SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 Report of Foreign Issuer Pursuant to Rule 13a - 16 or 15d - 16 of The Securities Exchange Act of 1934 Announcements sent to the London Stock Exchange National Grid plc, 1-3 Strand, London, WC2N 5EH, United Kingdom Update - Routine announcements in the period to April 2022 11 April 2022 National Grid plc ('

April 12, 2022 6-K

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Regi

SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April, 2022 Commission File Number: 001-14958 NATIONAL GRID plc (Registrant?s Name) 1-3 Strand London WC2N 5EH, England (Registrant?s Address) Indicate by check mark whether the registrant files or will file annual repo

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