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 from

2 June 2017 to 4 July 2017

4 July 2017

National Grid plc (“National Grid”)

ISIN Code: GB00BDR05C01

Transaction in Own Shares

National Grid announces that it has purchased the following number of its ordinary shares of 12^204/473p each on the London Stock Exchange from Barclays Capital Securities Limited (“Barclays”) as part of its buy-back programme announced on 2 June 2017. The sole purpose of the programme is, as previously announced, to reduce the share capital of National Grid as part of the return of proceeds to shareholders following the sale of a majority interest in National Grid’s UK gas distribution business.

National Grid intends to hold the purchased shares in treasury. Following the purchase of these shares, National Grid holds 181,840,877 of its ordinary shares in treasury and has 3,432,560,606 ordinary shares in issue (excluding treasury shares).

A schedule of individual trades carried out by Barclays (BARCGBN1) as principal in connection with the above purchases on 4 July 2017 is set out below.

Schedule of purchases — aggregate information

Schedule of purchases — individual transactions