Banco Santander (SAN) details €379M spent and 14.4% shares bought back

Rhea-AI Filing Summary

Banco Santander reports progress on its ongoing share buyback programme. Between 4 and 10 September 2025, the bank repurchased a total of 4,600,000 ordinary shares of SAN across several trading venues, as part of the programme approved by its Board of Directors.

The bank states that, up to 10 September 2025, the cash amount invested in repurchasing its own shares under this programme totals 379,079,294 Euros, representing approximately 22.3% of the maximum investment amount authorised for the buyback. It also indicates that these purchases bring total repurchases under the programme to about 14.4% of its outstanding shares as of 2021.

FORM 6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Report of Foreign Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities Exchange Act of 1934

For the month of September, 2025

Commission File Number: 001-12518

Banco Santander, S.A.

(Exact name of registrant as specified in its charter)

Ciudad Grupo Santander

28660 Boadilla del Monte (Madrid) Spain

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F X Form 40-F

Banco Santander, S.A.

TABLE OF CONTENTS

Item
1	Report of Other Relevant Information dated September 11, 2025

Item 1

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 September 2025 (both inclusive).

The cash amount of the shares purchased to 10 September 2025 as a result of the execution of the Buyback Programme amounts to 379,079,294 Euros, which represents approximately 22.3% 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 14.4% of its outstanding shares as of 2021.

Date	Security	Transaction	Trading venue	Number of shares	Weighted average price (€)
04/09/2025	SAN	Purchase	XMAD	361,969	8.0913
04/09/2025	SAN	Purchase	CEUX	23,402	8.1348
04/09/2025	SAN	Purchase	TQEX	10,156	8.1567
04/09/2025	SAN	Purchase	AQEU	4,473	8.0884
05/09/2025	SAN	Purchase	XMAD	1,256,987	8.1554
05/09/2025	SAN	Purchase	CEUX	81,783	8.1971
05/09/2025	SAN	Purchase	TQEX	34,785	8.1929
05/09/2025	SAN	Purchase	AQEU	26,445	8.2007
08/09/2025	SAN	Purchase	XMAD	849,061	8.2042
08/09/2025	SAN	Purchase	CEUX	67,990	8.2019
08/09/2025	SAN	Purchase	TQEX	25,190	8.2115
08/09/2025	SAN	Purchase	AQEU	57,759	8.1955
09/09/2025	SAN	Purchase	XMAD	831,458	8.2419
09/09/2025	SAN	Purchase	CEUX	111,652	8.2354
09/09/2025	SAN	Purchase	TQEX	21,572	8.2331
09/09/2025	SAN	Purchase	AQEU	35,318	8.2309
10/09/2025	SAN	Purchase	XMAD	676,960	8.4220
10/09/2025	SAN	Purchase	CEUX	73,946	8.4266
10/09/2025	SAN	Purchase	TQEX	17,245	8.4208
10/09/2025	SAN	Purchase	AQEU	31,849	8.4418
			TOTAL	4,600,000

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 September 2025

ANNEX I

Detailed information on each of the transactions carried out within the context of the Buy-back Programme between 04/09/2025 and 10/09/2025 (both inclusive)

(https://www.santander.com/content/dam/santander-com/es/documentos/cumplimiento/do-anexo-i-04-a-10-sept-2025.pdf)

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

			Banco Santander, S.A.
Date:	September 11, 2025		By:	/s/ Pedro de Mingo Kaminouchi
				Name:	Pedro de Mingo Kaminouchi
				Title:	Head of Corporate Compliance

FAQ

What does Banco Santander (SAN) report in this Form 6-K?

Banco Santander provides an update on its share buyback programme, detailing purchases of 4,600,000 ordinary shares between 4 and 10 September 2025 and summarising the cumulative cash invested and proportion of shares repurchased so far.

How much has Banco Santander invested in its buyback programme to 10 September 2025?

The bank reports that the cash amount invested in repurchasing its own shares under the buyback programme totals 379,079,294 Euros as of 10 September 2025.

What portion of the authorised buyback amount has Banco Santander used so far?

Banco Santander states that the 379,079,294 Euros invested up to 10 September 2025 represents approximately 22.3% of the maximum investment amount authorised for its share buyback programme.

What fraction of Banco Santander’s shares have been repurchased under the programme?

According to the update, the bank has repurchased approximately 14.4% of its outstanding shares as of 2021 through the buyback programme.

How many Banco Santander shares were repurchased between 4 and 10 September 2025?

During the period from 4 to 10 September 2025, Banco Santander repurchased a total of 4,600,000 ordinary shares of SAN across trading venues including XMAD, CEUX, TQEX and AQEU.

Where can investors find detailed transaction data for the Banco Santander buyback?

The bank indicates that detailed information on each transaction carried out between 4 and 10 September 2025 under the buyback programme is available in Annex I, accessible via the provided PDF link.

What type of shares are being repurchased in Banco Santander’s buyback programme?

The update specifies that the instrument involved is Banco Santander, S.A. ordinary shares, with ISIN code ES0113900J37.