Banco Santander, S.A. (the "Bank" or "Banco Santander"), in compliance with the Securities Market legislation, hereby communicates the following:

OTHER RELEVANT INFORMATION

End of the Buy-back Programme

Reference is made to our notice of inside information of 21 November 2022 (official registry number 1669), relating to the buyback programme of own shares (the "Buy-back Programme" or the "Programme") approved by the Board of Directors of Banco Santander. The Bank informs that, after the last acquisitions mentioned below, the maximum investment provided for in the Buy-back Programme was reached, having acquired a total of 340,406,572 own shares, representing approximately 2.03% of the Bank's share capital, for an aggregated amount of approximately 979 million euros (equivalent approximately to 20% of the Group's underlying profit for the first half of 2022). The acquisition of shares under the Buy-back Programme has been communicated on a regular basis, pursuant to the provisions of article 2.2 and 2.3 of the Commission Delegated Regulation (EU) No. 2016/1052. The Buy-back Programme has therefore been terminated as a consequence of the above and in accordance with the terms set out when it was announced.

As disclosed when the Buy-back Programme was launched, its purpose was to reduce the Bank's share capital by redeeming the shares acquired thereunder. The capital reduction, approved under section 7 D of the Agenda at the 2022 Ordinary General Shareholders' Meeting, second call held on 1 April 2022, will be implemented as soon as the relevant regulatory authorization from the European Central Bank is received.

Last transactions executed under the Programme.

Moreover, pursuant to article 5 of Regulation (EU) no. 596/2014 on Market Abuse of 16 April 2014, and articles 2.2 and 2.3 of Commission Delegated Regulation (EU) 2016/1052, of 8 March 2016, the Bank informs -on the basis of the information received from Goldman Sachs International as intermediary in charge of executing the Buy-back Programme- that the transactions executed as part of the Buy-back Programme, between 26 and 31 January 2023 (both inclusive) were as follows:

Issuer name: Banco Santander, S.A. - LEI 5493006QMFDDMYWIAM13

Reference of the financial instrument: ordinary shares - Code ISIN ES0113900J37

Detailed information of the transactions carried out within the referred period is attached as Annex I.

Boadilla del Monte (Madrid), 1 February 2023

ANNEX I

Detailed information on each of the transactions carried out within the context of the Buy-back Programme between 26 and 31 January 2023 (both inclusive)