v3.25.4
Credit impairment charges/(releases) - Narrative (Details) - GBP (£)
£ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of impairment loss and reversal of impairment loss [line items]      
Financial assets written and subject to enforcement activity, contractual amount outstanding £ 602 £ 500 £ 395
Amortised cost before modification 2,001 1,585 2,177
Net modification loss 80 75 2
Carrying amount of financial assets for which loss allowance has changed to 12-month measurement 221 £ 101 £ 149
Co-branded card portfolio | Assets and liabilities classified as held for sale      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Financial assets written and subject to enforcement activity, contractual amount outstanding £ 63    
Wholesale portfolios      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Changes in inputs, assumptions and estimation techniques used for ECL, probability 100.00%    
Wholesale portfolios | Bottom of range      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Inputs, assumptions and estimation techniques used for ECL, probability 0.20%    
Retail portfolios | Bottom of range | Minimum      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Inputs, assumptions and estimation techniques used for ECL, probability 50.00%    
Retail portfolios | Bottom of range | Maximum      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Inputs, assumptions and estimation techniques used for ECL, probability 100.00%    
Retail portfolios | Top of range      
Disclosure of impairment loss and reversal of impairment loss [line items]      
Inputs, assumptions and estimation techniques used for ECL, probability 400.00%