v3.26.1
Loans and advances to customers - Schedule of movement of gross exposure by impairment stage (Details) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year € (283,497) € (243,203)  
Impairment at end of year (300,026) (283,497) € (243,203)
Accumulated impairment      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 349 286  
Impairment at end of year 520 349 286
Customers      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year (1,054,069) (1,036,349)  
Impairment at end of year (1,037,288) (1,054,069) (1,036,349)
Customers | Financial instruments credit-impaired      
Disclosure of financial assets that are either past due or impaired [line items]      
Write-offs 13,266 13,212 13,847
Exchange differences and other changes 2,536 947 (168)
Customers | Accumulated impairment      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 22,125 22,788  
Impairment at end of year 21,158 22,125 22,788
Customers | Financial assets at fair value through other comprehensive income and financial assets at amortised cost | Accumulated impairment      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 1,043,436 1,039,608 1,042,174
Net changes on financial assets 52,443 26,776 14,805
Write-offs (13,266) (13,212) (13,847)
Exchange differences and other changes (63,680) (9,736) (3,524)
Impairment at end of year 1,018,933 1,043,436 1,039,608
Customers | Financial assets at fair value through other comprehensive income and financial assets at amortised cost | Accumulated impairment | Financial instruments not credit-impaired | Stage 1      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 925,413 929,133 942,861
To stage 2 from stage 1 (39,015) (49,316) (43,278)
To stage 3 from stage 1 (12,097) (11,517) (12,636)
To stage 1 from stage 2 16,079 21,475 15,180
To stage 1 from stage 3 441 447 488
Net changes on financial assets 69,819 43,281 29,696
Exchange differences and other changes (54,818) (8,090) (3,178)
Impairment at end of year 905,822 925,413 929,133
Customers | Financial assets at fair value through other comprehensive income and financial assets at amortised cost | Accumulated impairment | Financial instruments not credit-impaired | Stage 2 and 3      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 84,455 76,654 66,696
To stage 2 from stage 1 39,015 49,316 43,278
To stage 3 from stage 2 (8,266) (10,083) (9,915)
To stage 1 from stage 2 (16,079) (21,475) (15,180)
To stage 2 from stage 3 1,764 2,358 2,899
Net changes on financial assets (12,940) (11,616) (10,673)
Exchange differences and other changes (6,369) (699) (451)
Impairment at end of year 81,580 84,455 76,654
Customers | Financial assets at fair value through other comprehensive income and financial assets at amortised cost | Accumulated impairment | Financial instruments credit-impaired | Stage 2 and 3      
Disclosure of financial assets that are either past due or impaired [line items]      
Impairment at beginning of year 33,568 33,821 32,617
To stage 3 from stage 1 12,097 11,517 12,636
To stage 3 from stage 2 8,266 10,083 9,915
To stage 2 from stage 3 (1,764) (2,358) (2,899)
To stage 1 from stage 3 (441) (447) (488)
Net changes on financial assets (4,436) (4,889) (4,218)
Write-offs (13,266) (13,212) (13,847)
Exchange differences and other changes (2,493) (947) 105
Impairment at end of year € 31,531 € 33,568 € 33,821