Total Voting Rights

1 June 2016

National Grid plc (National Grid)

Voting Rights and Capital Update

National Grid's registered capital as at 31 May 2016 consisted of 3,924,038,086 ordinary shares, of which, 177,167,526 were held as treasury shares; leaving a balance of 3,746,870,560 shares with voting rights.

The figure of 3,746,870,560 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 and Transparency Rules.

Contact: A Morgan, Assistant Company Secretary, (0207 004 3228).