Holding(s) in Company

15 January 2015

National Grid plc (National Grid)

Notification of Major Interest in National Grid Ordinary Shares

National Grid has received a notification on Form TR-1 from The Capital Group Companies, Inc. that its total interest in National Grid voting ordinary shares was, at 13 January 2015, at 5.9739%, a total of 224,649,300 shares (previously notified at 3 December 2014, at 6.85%, a total of 258,130,404 shares).

This notice is in compliance with National Grid's obligations under the Disclosure and Transparency Rules.

David Whincup

Company Secretarial Assistant

0207 004 3209