Banco Santander, S.A. Auditor’s report, Annual accounts and director’s report for the year ended 31 December 2025 Translation of annual accounts originally issued in Spanish and prepared in accordance with the regulatory financial reporting framework applicable to Banco Santander in Spain (see notes 1 to 50). In the event of a discrepancy, the Spanish- language version prevails. .& Santander pwc -- This version of our report is a free translation of the original, which was prepared in Spanish. Al/ possible care has been taken to ensure that the translation is an accurate representation of the original. However, in al/ matters of interpretation of information, views or opinions, the original /anguage version of our report takes precedence over this translation Independent auditor's report on the annual accounts To the shareholders of Banco Santander, S.A. Report on the annual accounts Opinion We have audited the annual accounts of Banco Santander, S.A. (!he Bank), which comprise the balance sheet as al 31 December 2025, and the income statement, statement of recognised income and expense, statement of changes in total equity, statement of cash flows and related notes for the year then ended . In our opinion, the accompanying annual accounts present fairly, in all material respects, the equity and financia! position of the Bank as at 31 December 2025, as well as its financia! performance and cash flows for the year then ended, in accordance with the applicable financia! reporting framework (as identified in note 1 of the notes to the annual accounts), and in particular, with the accounting principies and criteria included therein. Basis for opinion We conducted our audit in accordance with legislation governing the audit practice in Spain. Our responsibilities under !hose standards are further described in the Auditor's responsibilities for the audit ofthe annual accounts section of our report. We are independent of the Bank in accordance with the ethical requirements, including those relating to independence, that are relevan! to our audit of the annual accounts in Spain, in accordance with legislation governing the audit practice. In this regard , we have not rendered services other than !hose relating to the audit of the accounts, and situations or circumstances have not arisen that, in accordance with the provisions of the aforementioned legislation, have affected our necessary independence such that it has been compromised. We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our opinion. Key audit matters Key audit matters are !hose matters that, in our professional judgment, were of most significance in our audit of the annual accounts of the curren! period. These matters were addressed in the context of our audit of the annual accounts as a whole, and in forming our opinion thereon, and we do not provide a separate opinion on these matters. PricewaterhouseCoopers Auditores, S.L. Torre PwC, Pº de la Castella na 259 B, 28046 Madrid, España Tel. : +34 915 684 400 / +34 902 021111 www.pwc.es R.M. Madrid, hoja M-63.988, folio 75, tomo 9 .267. libro 8.054 , sección J.• Inscrita en el R.OAC. con el numero S0242 - NIF: B-79031290 .& Santander Estimation of impairment of financia! assets at amortised cost - loans and advances to customers - for credit risk The models used to estímate the expected credit losses, especially !he updates made to consider !he curren! macroeconomic environment, entail a high complexity by incorporating estimates and judgments. These estimates require an elevated componen! of judgement by management and are one of the most significan! and complex estimates in the preparation of the annual accounts as at December 31 , 2025 included herein, therefare they have been considered one of !he key audit matters. The main judgements and assumptions used by management are the fallowing: • The estimation of the Probability of Default (PD) and Loss Given Default (LGD) parameters. • ldentification and classification of the staging criteria of loans and advances to customers. • The definition and evaluation of updates and adjustments to the expected credit loss models to adapt !he parameters estimated to the conditions and curren! environment. • The main assumptions used in the determination of the coverage over expected credit losses estimated individually. The Bank's business is facused on lending loans and advances to customers. As a result, far the year ended 2025 the Bank has recognised an amount of EUR 1,137 million of impairment of financia! assets at amortised cost. Please refer to Notes 2, 6, 1 O and 49 of the annual accounts as al December 31 , 2025. 2 We have obtained, in collaboration with our credit risk and economic farecasting experts, an understanding of management's process to estímate the impairment of financia! assets at amortised cost - loans and advances to customers - over the estimation of impairment of financia! assets assessed collectively and individually, including !he potential climate and geopolitical risk impact, on which we have made inquiries to management as part of our understanding audit procedures. In regards with the interna! control, we have facused on testing the design and operating effectiveness of key controls over !he fallowing processes: • Calculation methodologies, calibrations, monitoring and back-testing of the expected credit loss models performed by management. • Compliance with regulation and interna! policies, and the functionality of the interna! expected credit loss models approved by management, including the review process of models performed by the Interna! Validation Team. • Reliability of the data sources used in the calculalions and the suitability of the expected credit loss models taking into account the conditions and curren! environment. • Review process and approval of the macroeconomic variables used in the projections far the calculation of expected credit losses, as well as the updates to the models made by management derived from the conditions and curren! macroeconomic environment. • Periodic review process of borrowers to determine the proper staging criteria. • Review process of the expected credit loss coverage calculation derived from !he principal models and portfolios, as well as any adjustments deemed necessary, where applicable. Banco Santander, S.A. 6santander Litigation provisions and contingencies The Bank is party to a range of tax and legal proceedings - administrative and judicial - which primarily arise in the ordinary course of its operations. Also, there are other situations not yet subject to any judicial process that, however, have required the recognition of provisions, such as aspects of conduct with clients and the possible compensations that could be derived. • Loan collateral assignment and valuation process associated with mortgage collateral operations, including collateral recovery process. In addition, in collaboration with our credit risk, economic forecasting and real estate valuation experts we performed the following tests of details: • Tests of principal models with respect to: i) calculation and segmentation methods; ii) methodology used for the estimation of the expected credit loss parameters; iii) retrospective review of the model's performance; iv) data and main assumptions used , v) staging criteria and vi) information related to scenarios and their assumptions. • Evaluation of the updates to the expected credit loss models made by management due to the conditions and curren! macroeconomic environment. • Verification of the corree! consideration of the collaterals in the estímate of the impairment of loans, especially !hose that are classified as doubtful. • Reperformance of the collective provision calculation based on the expected credit loss models parameters, as well as any adjustments deemed necessary, where applicable. • Obtaining a sample of individual credit files to determine the adequacy of their accounting and classification , expected loss estimation methodologies, and, where appropriate, corresponding impairment. In the procedures described above, no exceptions were identified outside of a reasonable range. We have obtained, in collaboration with our experts in legal and tax matters, an understanding of the estimation process performed by management for litigation provisions and contingencies. Banco Santander, S.A. 3 .& Santander These procedures generally take a long period of time to run their course, giving rise to complex processes in accordance with the applicable legislation. In addition, the estímate of provisions requires the use of judgements by management, which are subject to uncertainty regarding the outcome of the proceedings. For these reasons, it has been considered one of the key audit matters. Management decides when to recognize a provision for these contingent liabilities, based on an estímate using certain procedures consisten! with the nature of the uncertainty of the obligations. Among these provisions, sorne of the most significan! are those for customer compensation for the sale of certain products; these estimates are based on the number of claims expected to be received , the number expected to be accepted, and the estimated average pay out per case. The amount of the litigation provisions and contingencies as at December 31, 2025 is EUR 815 million. Please refer to Notes 2 and 23 of the annual accounts as al December 31 , 2025. In regards with the interna! control , we have focused on testing the design and operating effectiveness of key controls over the following processes: • Additions, logs and updates over the completeness of the legal matters in the systems. • Accuracy of the key data, maintained in the systems, used in the calculation of the litigations provisions and contingencies. • Assessment of the criteria used to estímate the expected losses from litigation provisions and contingencies and evaluation of the adequacy over the calculation of the provisions for legal or tax procedures and their recognition. • Major minutes reconciliation of the tax inspections and the amounts accounted far. In addition, we have performed the following tests of details: • Analysis for reasonableness of the expected outcomes of the most significan! tax and legal proceedings. • Assessment of possible contingencies relating to compliance with the tax obligations for all the years open to inspection, of the communications with the regulatory bodies and analysis of the ongoing regulatory inspections. • Sending, obtaining and analysing, if any, audit confirmation letters from externa! and interna! lawyers and externa! tax advisors who work with the Bank or performing alternative procedures if confirmations are not received . • Analysis of the recognition and reasonableness of the provisions recorded . • Verifying the adequacy of the information disclosed in the annual accounts in accordance with applicable regulations. In the procedures described above, no exceptions were identified outside of a reasonable range. 4 Banco Santander, S.A.