Exhibit 12.4
RULE 13a-14(a) CERTIFICATION
I, Andrew Bonfield, certify that:
| 1. | I have reviewed this annual report on Form 20-F/A of National Grid plc; and |
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report. |
Date: 17 July 2017
/s/ Andrew Bonfield |
| Andrew Bonfield |
| Title: Finance Director |
| National Grid plc |
