v3.26.1
Fair value of financial instruments - Disclosure of changes in fair value of financial assets and liabilities calculated using internal models (Details) - Level 3 - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Changes in financial instruments, Assets      
Assets at beginning of period € 18,487 € 15,319 € 10,351
Purchases /Issuances 13,345 11,048 4,214
Sales/Settlements (9,198) (5,243) (3,798)
Changes in fair value recognized in profit or loss 405 403 280
Changes in fair value recognized in equity (73) (136) (204)
Transfers out of Level 3 of fair value hierarchy, assets (222) (779)  
Transfers into Level 3 of fair value hierarchy, assets     1,409
Other (1,089) (325) 160
Assets at end of period 15,319 10,351 8,290
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 1,352 1,227 925
Purchases, fair value measurement, liabilities 160 513 308
Sales/Settlements (256) (205) (318)
Changes in fair value recognized in profit or loss (64) (120) (124)
Gains (losses) recognised in other comprehensive income including exchange differences, fair value measurement, liabilities 0 0 (40)
Transfers out of Level 3 of fair value hierarchy, liabilities (101) (172)  
Transfers into Level 3 of fair value hierarchy, liabilities     471
Other 19 109 5
Liabilities at end of period 1,110 1,352 1,227
Financial liabilities held for trading      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 934 869 415
Purchases, fair value measurement, liabilities 160 472 276
Sales/Settlements (206) (200) (167)
Changes in fair value recognized in profit or loss (59) (95) (118)
Transfers out of Level 3 of fair value hierarchy, liabilities   (266)  
Transfers into Level 3 of fair value hierarchy, liabilities 16   476
Other 19 154 (13)
Liabilities at end of period 864 934 869
Financial liabilities held for trading | Derivatives      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 934 869 415
Purchases, fair value measurement, liabilities 160 472 276
Sales/Settlements (206) (200) (167)
Changes in fair value recognized in profit or loss (59) (95) (118)
Transfers out of Level 3 of fair value hierarchy, liabilities   (266)  
Transfers into Level 3 of fair value hierarchy, liabilities 16   476
Other 19 154 (13)
Liabilities at end of period 864 934 869
Financial liabilities held for trading | Swaps      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 479 388 235
Purchases, fair value measurement, liabilities 1 371 53
Sales/Settlements (88) (20) (83)
Changes in fair value recognized in profit or loss (90) (205) (58)
Transfers out of Level 3 of fair value hierarchy, liabilities   (105)  
Transfers into Level 3 of fair value hierarchy, liabilities 19   257
Other 97 50 (16)
Liabilities at end of period 418 479 388
Financial liabilities held for trading | Exchange rate options      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 0 8 0
Purchases, fair value measurement, liabilities 0 0 6
Sales/Settlements (1) (5) 0
Changes in fair value recognized in profit or loss 2 0 2
Transfers out of Level 3 of fair value hierarchy, liabilities   (3)  
Transfers into Level 3 of fair value hierarchy, liabilities 18   0
Other 15 0 0
Liabilities at end of period 34 0 8
Financial liabilities held for trading | Interest rate options      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 79 139 19
Purchases, fair value measurement, liabilities 0 0 4
Sales/Settlements (25) (54) (5)
Changes in fair value recognized in profit or loss 17 3 (16)
Transfers out of Level 3 of fair value hierarchy, liabilities (3) (10)  
Transfers into Level 3 of fair value hierarchy, liabilities     137
Other 27 1 0
Liabilities at end of period 95 79 139
Financial liabilities held for trading | Index and securities options      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 294 187 42
Purchases, fair value measurement, liabilities 1 54 88
Sales/Settlements (83) (14) (13)
Changes in fair value recognized in profit or loss 6 113 (15)
Transfers out of Level 3 of fair value hierarchy, liabilities (4) (40)  
Transfers into Level 3 of fair value hierarchy, liabilities     82
Other (63) (6) 3
Liabilities at end of period 151 294 187
Financial liabilities held for trading | Securities and interest rate futures      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 0    
Purchases, fair value measurement, liabilities 0    
Sales/Settlements 0    
Changes in fair value recognized in profit or loss 0    
Transfers out of Level 3 of fair value hierarchy, liabilities (19)    
Other 19    
Liabilities at end of period 0 0  
Financial liabilities held for trading | Other derivatives      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 82 147 119
Purchases, fair value measurement, liabilities 158 47 125
Sales/Settlements (9) (107) (66)
Changes in fair value recognized in profit or loss 6 (6) (31)
Transfers out of Level 3 of fair value hierarchy, liabilities   (108)  
Transfers into Level 3 of fair value hierarchy, liabilities 5   0
Other (76) 109 0
Liabilities at end of period 166 82 147
Hedging derivatives      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 12 6 14
Purchases, fair value measurement, liabilities 0 0 0
Sales/Settlements (1) 0 0
Changes in fair value recognized in profit or loss 14 0 (3)
Transfers out of Level 3 of fair value hierarchy, liabilities (6) 0 (5)
Other 0 6 0
Liabilities at end of period 19 12 6
Hedging derivatives | Swaps      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 12 6 14
Purchases, fair value measurement, liabilities 0 0 0
Sales/Settlements 0 0 0
Changes in fair value recognized in profit or loss 14 0 (3)
Transfers out of Level 3 of fair value hierarchy, liabilities (6) 0 (5)
Other (1) 6 0
Liabilities at end of period 19 12 6
Hedging derivatives | Interest rate options      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 0    
Purchases, fair value measurement, liabilities 0    
Sales/Settlements (1)    
Changes in fair value recognized in profit or loss 0    
Transfers out of Level 3 of fair value hierarchy, liabilities 0    
Other 1    
Liabilities at end of period 0 0  
Financial liabilities designated at fair value through profit or loss      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 160 29 151
Purchases, fair value measurement, liabilities 0 41 32
Sales/Settlements (49) (5) (151)
Changes in fair value recognized in profit or loss 0 1 (3)
Transfers out of Level 3 of fair value hierarchy, liabilities (111)    
Transfers into Level 3 of fair value hierarchy, liabilities   94 0
Other 0 0 0
Liabilities at end of period 0 160 29
Interest rate options      
Changes in financial instruments, Liabilities      
Liabilities at beginning of period 246 323 345
Purchases, fair value measurement, liabilities 0 0 0
Sales/Settlements 0 0 0
Changes in fair value recognized in profit or loss (19) (26) 0
Gains (losses) recognised in other comprehensive income including exchange differences, fair value measurement, liabilities 0 0 (40)
Transfers out of Level 3 of fair value hierarchy, liabilities 0 0  
Transfers into Level 3 of fair value hierarchy, liabilities     0
Other 0 (51) 18
Liabilities at end of period 227 246 323
Financial assets held for trading      
Changes in financial instruments, Assets      
Assets at beginning of period 6,496 3,930 2,086
Purchases /Issuances 5,353 3,205 496
Sales/Settlements (2,748) (813) (149)
Changes in fair value recognized in profit or loss 57 302 194
Transfers out of Level 3 of fair value hierarchy, assets (9) (715)  
Transfers into Level 3 of fair value hierarchy, assets     1,162
Other (87) (135) 0
Assets at end of period 3,930 2,086 383
Financial assets held for trading | Central banks      
Changes in financial instruments, Assets      
Assets at beginning of period 441 0  
Purchases /Issuances 437    
Sales/Settlements 0    
Changes in fair value recognized in profit or loss 4    
Transfers out of Level 3 of fair value hierarchy, assets 0    
Other 0    
Assets at end of period 0    
Financial assets held for trading | Credit institutions      
Changes in financial instruments, Assets      
Assets at beginning of period 152 769 0
Purchases /Issuances 128 770  
Sales/Settlements (744) 0  
Changes in fair value recognized in profit or loss 0 (1)  
Transfers out of Level 3 of fair value hierarchy, assets 0 0  
Other (1) 0  
Assets at end of period 769 0  
Financial assets held for trading | Customers      
Changes in financial instruments, Assets      
Assets at beginning of period 4,592 1,801 24
Purchases /Issuances 4,450 1,808 23
Sales/Settlements (1,711) (24) 0
Changes in fair value recognized in profit or loss 52 (7) 1
Transfers out of Level 3 of fair value hierarchy, assets   0  
Transfers into Level 3 of fair value hierarchy, assets 2   0
Other (2) 0 0
Assets at end of period 1,801 24 0
Financial assets held for trading | Debt securities      
Changes in financial instruments, Assets      
Assets at beginning of period 340 413 914
Purchases /Issuances 110 355 126
Sales/Settlements (112) (384) (63)
Changes in fair value recognized in profit or loss (13) (39) 30
Transfers out of Level 3 of fair value hierarchy, assets (21) (377)  
Transfers into Level 3 of fair value hierarchy, assets     773
Other (37) (56) 6
Assets at end of period 413 914 42
Financial assets held for trading | Equity instruments      
Changes in financial instruments, Assets      
Assets at beginning of period   0 1
Purchases /Issuances   0 0
Sales/Settlements   0 0
Changes in fair value recognized in profit or loss   (1) 0
Transfers out of Level 3 of fair value hierarchy, assets   0  
Transfers into Level 3 of fair value hierarchy, assets     0
Other   0 0
Assets at end of period 0 1 1
Financial assets held for trading | Derivatives      
Changes in financial instruments, Assets      
Assets at beginning of period 971 947 1,147
Purchases /Issuances 228 272 347
Sales/Settlements (181) (405) (86)
Changes in fair value recognized in profit or loss 14 350 163
Transfers out of Level 3 of fair value hierarchy, assets   (338)  
Transfers into Level 3 of fair value hierarchy, assets 10   389
Other (47) (79) (6)
Assets at end of period 947 1,147 340
Financial assets held for trading | Swaps      
Changes in financial instruments, Assets      
Assets at beginning of period 551 556 577
Purchases /Issuances 1 184 90
Sales/Settlements (81) (278) (4)
Changes in fair value recognized in profit or loss (30) 186 179
Transfers out of Level 3 of fair value hierarchy, assets (21) (152)  
Transfers into Level 3 of fair value hierarchy, assets     191
Other 126 39 (18)
Assets at end of period 556 577 139
Financial assets held for trading | Exchange rate options      
Changes in financial instruments, Assets      
Assets at beginning of period 39 2 9
Purchases /Issuances 0 0 1
Sales/Settlements 0 (1) 0
Changes in fair value recognized in profit or loss 5 0 4
Transfers out of Level 3 of fair value hierarchy, assets   (6)  
Transfers into Level 3 of fair value hierarchy, assets 19   0
Other 13 0 0
Assets at end of period 2 9 4
Financial assets held for trading | Interest rate options      
Changes in financial instruments, Assets      
Assets at beginning of period 39 30 153
Purchases /Issuances 6 13 0
Sales/Settlements 0 (42) 0
Changes in fair value recognized in profit or loss 1 (20) 2
Transfers out of Level 3 of fair value hierarchy, assets   (74)  
Transfers into Level 3 of fair value hierarchy, assets 20   112
Other (18) 0 0
Assets at end of period 30 153 39
Financial assets held for trading | Index and securities options      
Changes in financial instruments, Assets      
Assets at beginning of period 120 241 235
Purchases /Issuances 1 42 132
Sales/Settlements (41) (44) (4)
Changes in fair value recognized in profit or loss 37 128 (20)
Transfers out of Level 3 of fair value hierarchy, assets (5) (106)  
Transfers into Level 3 of fair value hierarchy, assets     76
Other (113) (14) 3
Assets at end of period 241 235 48
Financial assets held for trading | Interest rate futures      
Changes in financial instruments, Assets      
Assets at beginning of period 0 0  
Purchases /Issuances 0    
Sales/Settlements (14)    
Changes in fair value recognized in profit or loss 0    
Transfers out of Level 3 of fair value hierarchy, assets (6)    
Other 20    
Assets at end of period 0    
Financial assets held for trading | Other derivatives      
Changes in financial instruments, Assets      
Assets at beginning of period 222 118 173
Purchases /Issuances 220 33 124
Sales/Settlements (45) (40) (78)
Changes in fair value recognized in profit or loss 1 56 (2)
Transfers out of Level 3 of fair value hierarchy, assets   0  
Transfers into Level 3 of fair value hierarchy, assets 3   10
Other (75) (104) 9
Assets at end of period 118 173 110
Hedging derivatives      
Changes in financial instruments, Assets      
Assets at beginning of period 7 20 0
Purchases /Issuances 0 0  
Sales/Settlements 0 0  
Changes in fair value recognized in profit or loss (7) 15  
Transfers out of Level 3 of fair value hierarchy, assets (4) (1)  
Other (2) 6  
Assets at end of period 20 0  
Hedging derivatives | Swaps      
Changes in financial instruments, Assets      
Assets at beginning of period 7 20 0
Purchases /Issuances 0 0  
Sales/Settlements 0 0  
Changes in fair value recognized in profit or loss (7) 15  
Transfers out of Level 3 of fair value hierarchy, assets (4) (1)  
Other (2) 6  
Assets at end of period 20 0  
Financial assets at fair value through profit or loss      
Changes in financial instruments, Assets      
Assets at beginning of period 34 106 181
Purchases /Issuances 33 417 51
Sales/Settlements (100) (300) 0
Changes in fair value recognized in profit or loss (5) 13 (21)
Transfers out of Level 3 of fair value hierarchy, assets 0 (201)  
Transfers into Level 3 of fair value hierarchy, assets     22
Other 0 (4) (298)
Assets at end of period 106 181 427
Financial assets at fair value through profit or loss | Customers      
Changes in financial instruments, Assets      
Assets at beginning of period 14 20 31
Purchases /Issuances 0 0 0
Sales/Settlements 0 0 0
Changes in fair value recognized in profit or loss (5) (5) 4
Transfers out of Level 3 of fair value hierarchy, assets 0 (23)  
Transfers into Level 3 of fair value hierarchy, assets     22
Other (1) 17 0
Assets at end of period 20 31 5
Financial assets at fair value through profit or loss | Debt securities      
Changes in financial instruments, Assets      
Assets at beginning of period 20 86 150
Purchases /Issuances 33 417 51
Sales/Settlements (100) (300) 0
Changes in fair value recognized in profit or loss 0 18 (25)
Transfers out of Level 3 of fair value hierarchy, assets 0 (178)  
Transfers into Level 3 of fair value hierarchy, assets     0
Other 1 (21) (298)
Assets at end of period 86 150 422
Non-trading financial assets mandatorily at fair value through profit or loss      
Changes in financial instruments, Assets      
Assets at beginning of period 2,889 2,588 2,095
Purchases /Issuances 324 719 345
Sales/Settlements (191) (349) (238)
Changes in fair value recognized in profit or loss 360 73 107
Transfers out of Level 3 of fair value hierarchy, assets (266)   (6)
Transfers into Level 3 of fair value hierarchy, assets   132  
Other 74 (82) 54
Assets at end of period 2,588 2,095 1,833
Non-trading financial assets mandatorily at fair value through profit or loss | Customers      
Changes in financial instruments, Assets      
Assets at beginning of period 171 505 287
Purchases /Issuances 0 390 99
Sales/Settlements 0 (128) (73)
Changes in fair value recognized in profit or loss (36) (31) 13
Transfers out of Level 3 of fair value hierarchy, assets (266)   0
Transfers into Level 3 of fair value hierarchy, assets   41  
Other (32) (54) 9
Assets at end of period 505 287 239
Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities      
Changes in financial instruments, Assets      
Assets at beginning of period 175 242 313
Purchases /Issuances 24 4 38
Sales/Settlements (40) (96) (48)
Changes in fair value recognized in profit or loss (27) 10 (5)
Transfers out of Level 3 of fair value hierarchy, assets 0   0
Transfers into Level 3 of fair value hierarchy, assets   11  
Other (24) 0 3
Assets at end of period 242 313 325
Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments      
Changes in financial instruments, Assets      
Assets at beginning of period 2,543 1,841 1,495
Purchases /Issuances 300 325 208
Sales/Settlements (151) (125) (117)
Changes in fair value recognized in profit or loss 423 94 99
Transfers out of Level 3 of fair value hierarchy, assets     (6)
Transfers into Level 3 of fair value hierarchy, assets 0 80  
Other 130 (28) 42
Assets at end of period 1,841 1,495 1,269
Financial assets at fair value through other comprehensive income      
Changes in financial instruments, Assets      
Assets at beginning of period 9,061 8,675 5,989
Purchases /Issuances 7,635 6,707 3,322
Sales/Settlements (6,159) (3,781) (3,411)
Changes in fair value recognized in profit or loss 0 0 0
Changes in fair value recognized in equity (73) (136) (204)
Transfers into Level 3 of fair value hierarchy, assets 57 6 231
Other (1,074) (110) 404
Assets at end of period 8,675 5,989 5,647
Financial assets at fair value through other comprehensive income | Loans and advances      
Changes in financial instruments, Assets      
Assets at beginning of period 7,902 7,253 4,938
Purchases /Issuances 7,259 5,962 3,322
Sales/Settlements (5,621) (3,685) (3,408)
Changes in fair value recognized in profit or loss 0 0 0
Changes in fair value recognized in equity (87) 43 36
Transfers into Level 3 of fair value hierarchy, assets 97 0 160
Other (999) (5) 110
Assets at end of period 7,253 4,938 4,718
Financial assets at fair value through other comprehensive income | Debt securities      
Changes in financial instruments, Assets      
Assets at beginning of period 887 1,047 559
Purchases /Issuances 360 743 0
Sales/Settlements (530) (81) 0
Changes in fair value recognized in profit or loss 0 0 0
Changes in fair value recognized in equity 16 (74) 5
Transfers out of Level 3 of fair value hierarchy, assets (40)    
Transfers into Level 3 of fair value hierarchy, assets   6 71
Other 34 (106) 254
Assets at end of period 1,047 559 229
Financial assets at fair value through other comprehensive income | Equity instruments      
Changes in financial instruments, Assets      
Assets at beginning of period 272 375 492
Purchases /Issuances 16 2 0
Sales/Settlements (8) (15) (3)
Changes in fair value recognized in profit or loss 0 0 0
Changes in fair value recognized in equity (2) (105) (245)
Transfers out of Level 3 of fair value hierarchy, assets 0    
Transfers into Level 3 of fair value hierarchy, assets   0 0
Other (109) 1 40
Assets at end of period € 375 € 492 € 700