Total Voting Rights

2 May 2017

National Grid plc (National Grid)

Voting Rights and Capital Update

National Grid's registered capital as at 30 April 2017 consisted of 3,942,983,436 ordinary shares, of which, 189,744,953 were held as treasury shares; leaving a balance of 3,753,238,483 shares with voting rights.

The figure of 3,753,238,483 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).