Sant Uk.10te% Regulatory News (SAN)

Abbey National Treasury Services plc(incorporated in England and Wales with registered number 2338548)

and

SANTANDER UK PLC(incorporated in England and Wales with registered number 2294747)

NOTICE OF Substitution of Issuer

to the holders of:

Series 51A "European Style" Put Warrants Linked to an Equity Index (ISIN: GB00B7F7K827)

Series 51B "European Style" Call Warrants Linked to an Equity Index (ISIN: GB00B7F7K595)(together, the "Warrants")

each issued by Abbey National Treasury Services plc under itsProgramme for the issuance of Warrantsunconditionally and irrevocably guaranteed by Santander UK plc

NOTICE IS HEREBY GIVEN that, with effect on and from 1 November 2017 (the "Effective Date") Santander UK plc will be substituted in place of Abbey National Treasury Services plc as principal obligor under the Warrants. This substitution will be effected pursuant to a deed of substitution, novation and amendment dated 16 October 2017 entered into between, inter alios, Abbey National Treasury Services plc as original issuer, Santander UK plc as new issuer, and Citibank N.A. as principal warrant agent (the "Deed of Substitution, Novation and Amendment").

Copies of the Deed of Substitution, Novation and Amendment are available for inspection from the principal warrant agent whose address is:

Citibank N.A.Citigroup Centre

Canada Square

Canary Wharf

London

E14 5LBUnited Kingdom

For further information regarding the matters set out in this notice, please contact:

Structured Notes DeskSantander UK plc2 Triton SquareRegent's PlaceLondon NW1 3AN

Tel: +44 (0)20 7756 7000

Email: structurednotesafm@santander.co.uk

This notice does not constitute or form part of an offer to sell or the solicitation of an offer to subscribe for or otherwise acquire any securities.