v3.26.1
Marketable debt securities - Disclosure of changes in bonds and debentures outstanding (Details) - Marketable debt securities - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Changes in financial instruments, Liabilities      
Balance at beginning of year € 325,521 € 308,579  
Balance at year-end 324,390 325,521 € 308,579
Bonds and debentures outstanding      
Changes in financial instruments, Liabilities      
Balance at beginning of year 252,765 231,880 211,597
Net inclusion, fair value measurement, liabilities 0 (1,224) (1,467)
Issues 72,014 77,921 68,568
Redemptions and repurchases (60,335) (57,676) (48,825)
Exchange differences and other movements (10,551) 1,864 2,007
Balance at year-end 253,893 252,765 231,880
Bonds and debentures outstanding | Banco Santander, S.A.      
Changes in financial instruments, Liabilities      
Issues 12,682 20,559 19,706
Redemptions and repurchases (14,854) (15,888) (7,889)
Bonds and debentures outstanding | SPIRE SA Compartment 2023-374      
Changes in financial instruments, Liabilities      
Net inclusion, fair value measurement, liabilities 0 (1,224) 0
Bonds and debentures outstanding | Auto ABS UK Loans PLC      
Changes in financial instruments, Liabilities      
Net inclusion, fair value measurement, liabilities 0 0 (841)
Bonds and debentures outstanding | PSA Bank Deutschland GmbH      
Changes in financial instruments, Liabilities      
Net inclusion, fair value measurement, liabilities 0 0 (626)
Bonds and debentures outstanding | Banco Santander (Brasil) S.A.      
Changes in financial instruments, Liabilities      
Issues 11,827 8,039 12,781
Redemptions and repurchases (9,430) (6,919) (10,542)
Bonds and debentures outstanding | Santander Group UK      
Changes in financial instruments, Liabilities      
Issues 11,450 9,884 6,002
Redemptions and repurchases (4,936) (7,764) (6,185)
Bonds and debentures outstanding | Santander Consumer USA Holdings Inc.      
Changes in financial instruments, Liabilities      
Issues 8,705 8,949 7,309
Redemptions and repurchases (7,905) (10,806) (14,466)
Bonds and debentures outstanding | Santander International Products, Plc.      
Changes in financial instruments, Liabilities      
Issues 5,071 2,752 1,054
Redemptions and repurchases (1,327) (584) (728)
Bonds and debentures outstanding | Stellantis Financial Services Italia S.p.A.      
Changes in financial instruments, Liabilities      
Issues 2,020 2,021 761
Redemptions and repurchases (698) (22) 0
Bonds and debentures outstanding | Santander Consumer Bank S.p.A.      
Changes in financial instruments, Liabilities      
Issues 1,799 1,001 1,460
Redemptions and repurchases (1,327) (233) (266)
Bonds and debentures outstanding | Santander Holdings USA, Inc.      
Changes in financial instruments, Liabilities      
Issues 1,772 3,004 1,850
Redemptions and repurchases (2,693) (1,387) 0
Bonds and debentures outstanding | Fondo de Titulización, Santander Consumo 8      
Changes in financial instruments, Liabilities      
Issues 1,523 0 0
Bonds and debentures outstanding | Fondo de Titulización, Santander Consumo 9      
Changes in financial instruments, Liabilities      
Issues 1,421 0 0
Bonds and debentures outstanding | Banco Santander - Chile      
Changes in financial instruments, Liabilities      
Issues 1,204 1,171 814
Redemptions and repurchases (1,930) (1,486) (575)
Bonds and debentures outstanding | Santander Consumer Finance, S.A.      
Changes in financial instruments, Liabilities      
Issues 1,181 2,271 2,557
Redemptions and repurchases (2,743) (2,900) (1,800)
Bonds and debentures outstanding | Banco Santander Totta, S.A.      
Changes in financial instruments, Liabilities      
Issues 1,069 1,129 1,734
Redemptions and repurchases (223) (1,055) (108)
Bonds and debentures outstanding | Santander Bank, National Association      
Changes in financial instruments, Liabilities      
Issues 853 4,133 1,346
Redemptions and repurchases (2,648) (1,440) (567)
Bonds and debentures outstanding | SC Germany S.A., Compartment Consumer 2025-2      
Changes in financial instruments, Liabilities      
Issues 850 0 0
Bonds and debentures outstanding | SC Austria S.à r.l., Compartment Consumer 2025-1      
Changes in financial instruments, Liabilities      
Issues 803 0 0
Bonds and debentures outstanding | Secucor Finance 2025-1 Designated Activity Company      
Changes in financial instruments, Liabilities      
Issues 801 0 0
Bonds and debentures outstanding | Banco Santander México, S.A., Institución de Banca Múltiple, Grupo Financiero Santander México      
Changes in financial instruments, Liabilities      
Issues 787 875 634
Redemptions and repurchases (2,084) (122) (140)
Bonds and debentures outstanding | Hyundai Capital Bank Europe GmbH Italy      
Changes in financial instruments, Liabilities      
Issues 749 0 0
Bonds and debentures outstanding | Banque Stellantis France      
Changes in financial instruments, Liabilities      
Issues 728 897 1,145
Redemptions and repurchases (746) (565) (813)
Bonds and debentures outstanding | Santander Consumer Bank AG      
Changes in financial instruments, Liabilities      
Issues 0 180 1,256
Bonds and debentures outstanding | SC Germany S.A., Compartment Consumer 2024-1      
Changes in financial instruments, Liabilities      
Issues 0 1,500 0
Bonds and debentures outstanding | Santander Consumo 6, F.T.      
Changes in financial instruments, Liabilities      
Issues 0 1,230 0
Bonds and debentures outstanding | Santander Consumo 7, F.T.      
Changes in financial instruments, Liabilities      
Issues 0 1,218 0
Bonds and debentures outstanding | Santander Bank Polska S.A.      
Changes in financial instruments, Liabilities      
Issues 0 1,002 1,102
Bonds and debentures outstanding | SC Germany S.A., Compartment Consumer 2024-2      
Changes in financial instruments, Liabilities      
Issues 0 1,000 0
Bonds and debentures outstanding | Santander Consumer Bank AS      
Changes in financial instruments, Liabilities      
Redemptions and repurchases € (1,174) € (839) € (681)