Director/PDMR Shareholding

1

Details of the person discharging managerial responsibilities / person closely associated

a)

Name

Mike Westcott

2

Reason for the notification

a)

Position/status

Group HR Director

b)

Initial notification /Amendment

Initial notification

3

Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor

a)

Name

National Grid plc

b)

LEI

8R95QZMKZLJX5Q2XR704

4

Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transactions have been conducted

a)

Description of the financial instrument, type of instrument

Identification code

Ordinary shares of 12 204/473p each

GB00BDR05C01

b)

Nature of the transaction

Acquisition of a conditional award over securities, for nil consideration, under the Long Term Performance Plan. The extent to which the award will vest will depend upon the Company's performance against the relevant conditions. Subject to performance, the shares will vest in July 2020 and the shares will be transferred to the participant net of deductions.

c)

Price(s) and volume(s)

d)

Aggregated information

- Aggregated volume

- Price

e)

Date of the transaction

2017.07.24

f)

Place of the transaction

Outside a trading venue

Name of officer of issuer responsible for making notification: Robin Kerner.

Date of notification: 2017.07.25