NOTIFICATION OF SHARE REPURCHASE PROGRAMME

28 January 2022

For immediate release

Pennon Group plc

Share Repurchase Programme

The first three phases of Pennon's previously announced on-market share buy-back programme of up to c. £400 million (the "Programme") have deployed c.£150 million in total over the period from 23 July 2021 to 7 January 2022.

Pennon is announcing today that it is initiating the fourth phase of the Programme and has entered into a non-discretionary agreement with Morgan Stanley & Co. International plc ("Morgan Stanley") to enable Morgan Stanley, acting as principal, to purchase ordinary shares of 61.05 pence each in the share capital of Pennon for an aggregate purchase price of no greater than £50 million and the simultaneous on-sale of such shares by Morgan Stanley to Pennon. This agreement commences on 28 January 2022 and share purchase activity pursuant to the agreement is expected to end no later than 18 March 2022. Morgan Stanley will make trading decisions in relation to Pennon shares purchased under the Programme independently of, and uninfluenced by, Pennon. All shares repurchased will be cancelled.

Full deployment of the Programme is subject to Pennon's continued review of value creating opportunities in the UK water sector.

Any purchase of Pennon shares done in relation to this announcement will be carried out on the London Stock Exchange and Multilateral Trading Facilities, as defined by the Directive 2014/65/EU on markets in financial instruments (including the delegated and implementing acts adopted under it) as implemented, retained, amended, extended, re-enacted or otherwise given effect in the United Kingdom from 1 January 2021 and as amended or supplemented in the United Kingdom thereafter, and executed within the price and volume conditions set out in the Listing Rules, the provisions of Article 5(1) of Regulation (EU) No. 596/2014 (as incorporated into UK domestic law by the European Union (Withdrawal) Act 2018), the Commission Delegated Regulation (EU) 2016/1052 (as incorporated into UK domestic law by the European Union (Withdrawal) Act 2018) dealing with buyback programmes and the Company's general authority to make market purchases of Pennon shares granted at its AGM on 22 July 2021.

The Company will announce any market repurchase of shares no later than 7.30 a.m. on the business day following the calendar day on which the repurchase occurred.

This announcement does not constitute, or form part of, an offer or any solicitation of an offer for securities in any jurisdiction.

BACKGROUND

As detailed in Pennon's Trading Statement on 28 September 2021, and in line with the package of shareholder returns announced by Pennon in June 2021, and approved by shareholders at the 2021 Annual General Meeting, authority was granted for the proposed on-market share buy-back programme (the "Programme") in respect of its ordinary shares of 61.05 pence each, of up to c. £400 million.

The purpose of the Programme is to reduce share capital, and completion of the Programme is subject to Pennon's continued review of value creating opportunities in the UK water sector, where the maximum number of shares that can be repurchased in connection with the Programme is 42,183,689 (being the maximum authority granted by shareholders at Pennon's AGM on 22 July 2021). Any further phases are expected to commence over the period to 30 September 2022.