National Storage Mechanism | Additional information

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 7 and 13 August 2025 (both inclusive).

The cash amount of the shares purchased to 13 August 2025 as a result of the execution of the Buyback Programme amounts to 214,649,085 Euros, which represents approximately 12.6% 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 14.3% of its outstanding shares as of 2021.

Date	Security	Transaction	Trading venue	Number of shares	Weighted average price (€)
07/08/ 2025	SAN	Purchase	XMAD	1,670,260	7.7116
07/08/ 2025	SAN	Purchase	CEUX	327,054	7.7234
07/08/ 2025	SAN	Purchase	TQEX	128,677	7.7201
07/08/ 2025	SAN	Purchase	AQEU	124,009	7.7143
08/08/ 2025	SAN	Purchase	XMAD	1,186,872	7.8572
08/08/ 2025	SAN	Purchase	CEUX	119,148	7.8633
08/08/ 2025	SAN	Purchase	TQEX	40,902	7.8622
08/08/ 2025	SAN	Purchase	AQEU	53,078	7.8597
11/08/ 2025	SAN	Purchase	XMAD	1,330,929	7.9124
11/08/ 2025	SAN	Purchase	CEUX	150,501	7.9167
11/08/ 2025	SAN	Purchase	TQEX	58,392	7.9029
11/08/ 2025	SAN	Purchase	AQEU	60,178	7.9056
12/08/ 2025	SAN	Purchase	XMAD	1,156,697	8.0131
12/08/ 2025	SAN	Purchase	CEUX	217,546	8.0149
12/08/ 2025	SAN	Purchase	TQEX	66,106	8.0090
12/08/ 2025	SAN	Purchase	AQEU	59,651	8.0101
13/08/ 2025	SAN	Purchase	XMAD	541,926	8.0968
13/08/ 2025	SAN	Purchase	CEUX	43,015	8.0859
13/08/ 2025	SAN	Purchase	TQEX	14,513	8.0747
13/08/ 2025	SAN	Purchase	AQEU	546	8.0470
			TOTAL	7,350,000

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), 14 August 2025

ANNEX I

Detailed information on each of the transactions carried out within the context of the Buy-back Programme between 07/08/2025 and 13/08/2025 (both inclusive)