Publication of Supplement to Prospectus

The following supplementary prospectus has been approved by the Financial Conduct Authority and is available for viewing:

Supplementary Prospectus dated 8 June 2023 (the "Supplement") relating to the £5,000,000,000 Euro Medium Term Note Programme (the "Programme") established by each of Southern Gas Networks PLC and Scotland Gas Networks PLC (together, the "Issuers").

The Supplement should be read and construed in conjunction with the base prospectus dated 27 September 2022 relating to the Programme (the "Prospectus").

To view the Supplement, please paste the following URL into the address bar of your browser.

http://www.rns-pdf.londonstockexchange.com/rns/1454C_1-2023-6-8.pdf

The Supplement is available on the Issuers' website at https://www.sgn.co.uk/about-us/debt-investor-relations and is also available for review at St Lawrence House, Station Approach, Horley, Surrey, RH6 9HJ.

A copy of the Supplement has been submitted to the National Storage Mechanism and will shortly be available for inspection at: https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

For further information, please contact:

Scotland Gas Networks PLC and Southern Gas Networks PLC

Alexander Rutherford

Group Treasurer

St Lawrence House

Station Approach

Horley, Surrey

RH6 9HJ

Tel: 07971 239 190

Email: [email protected]

DISCLAIMER - INTENDED ADDRESSEES

Please note that the information contained in the Prospectus may be addressed to and/or targeted at persons who are residents of particular countries (specified in the Prospectus) only and is not intended for use and should not be relied upon by any person outside these countries and/or to whom the offer contained in the Prospectus is not addressed. Prior to relying on the information contained in the Prospectus you must ascertain from the Prospectus whether or not you are part of the intended addressees of the information contained therein.

In particular, the Prospectus does not constitute an offer of securities for sale in the United States. This is not for distribution in the United States. The securities described herein have not been, and will not be, registered under the U.S. Securities Act of 1933, as amended (the "Securities Act"), or under any relevant securities laws of any state of the United States of America and are subject to U.S. tax law requirements. Subject to certain exceptions, the securities may not be offered or sold within the United States or to, or for the account or benefit of, U.S. persons or to persons within the United States of America, as such terms are defined in Regulation S under the Securities Act. There will be no public offering of the securities in the United States.

Your right to access this service is conditional upon complying with the above requirement.

This information is provided by RNS, the news service of the London Stock Exchange

END