Banco Santander S.A.

Capital/Financing Update • Dec 11, 2025

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

OTHER RELEVANT INFORMATION

Reference is made to our notice of inside information of 30 July 2025 (official registry number 2844) (the "Buyback Commencement Communication"), relating to the buyback programme of own shares (the "Buyback Programme") approved by the Board of Directors of Banco Santander.

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 of the transactions carried out over its own shares between 4 and 10 December 2025 (both inclusive).

The cash amount of the shares purchased to 10 December 2025 as a result of the execution of the Buyback Programme amounts to 1,505,372,814 Euros, which represents approximately 88.6% of the maximum investment amount of the Buyback Programme. The programme was announced together with its other characteristics through the Buyback Commencement Communication. With these purchases, the Bank has repurchased approximately 15.2% of its outstanding shares as of 2021.

Date	Security	Transaction	Trading venue	Number of shares	Weighted average price (€)
04/12/2025	SAN	Purchase	XMAD	1,063,650	9.3818
04/12/2025	SAN	Purchase	CEUX	78,181	9.3752
04/12/2025	SAN	Purchase	TQEX	20,767	9.3624
04/12/2025	SAN	Purchase	AQEU	37,402	9.3787
05/12/2025	SAN	Purchase	XMAD	1,105,754	9.5537
05/12/2025	SAN	Purchase	CEUX	105,783	9.5453
05/12/2025	SAN	Purchase	TQEX	31,893	9.5337
05/12/2025	SAN	Purchase	AQEU	56,570	9.5516
08/12/2025	SAN	Purchase	XMAD	548,807	9.3994
08/12/2025	SAN	Purchase	CEUX	93,160	9.4125
08/12/2025	SAN	Purchase	TQEX	20,035	9.4068
08/12/2025	SAN	Purchase	AQEU	37,998	9.4041
09/12/2025	SAN	Purchase	XMAD	1,582,767	9.5120
09/12/2025	SAN	Purchase	CEUX	203,526	9.5166
09/12/2025	SAN	Purchase	TQEX	77,756	9.5077
09/12/2025	SAN	Purchase	AQEU	35,951	9.5119
10/12/2025	SAN	Purchase	XMAD	1,839,866	9.5493
10/12/2025	SAN	Purchase	CEUX	117,976	9.5517
10/12/2025	SAN	Purchase	TQEX	42,158	9.5515
			TOTAL	7,100,000

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), 11 December 2025

ANNEX I

Detailed information on each of the transactions carried out within the context of the Buy-back Programme between 04/12/2025 and 10/12/2025 (both inclusive)