Total Voting Rights

1 November 2017

National Grid plc (National Grid)

Voting Rights and Capital Update

National Grid's registered capital as at 31 October 2017 consisted of 3,617,570,125 ordinary shares, of which, 220,208,763 were held as treasury shares; leaving a balance of 3,397,361,362 shares with voting rights.

The figure of 3,397,361,362 may be used by shareholders as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, National Grid under the FCA Disclosure Guidance and Transparency Rules.

Contact: C James, Company Secretarial Assistant, (0207 004 3116).