v3.26.1
Allowance for expected credit losses - Disclosure of Application of Judgement in Adjustments to Modelled ECL (Details) - Allowance for expected credit losses - GBP (£)
£ in Millions
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses £ 2,636 £ 2,622    
Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 369 354    
Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 142 225    
Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 3,147 3,201 £ 3,374 £ 3,453
UK mortgages | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 602 623    
UK mortgages | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 0 0    
UK mortgages | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 67 108    
UK mortgages | Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 669 731 709 852
Credit cards | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 589 540    
Credit cards | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 0 0    
Credit cards | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 56 63    
Credit cards | Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 645 603 659 674
Other Retail | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 909 916    
Other Retail | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 0 0    
Other Retail | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 73 75    
Other Retail | Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 982 991 1,010 950
Commercial Banking | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 535 542    
Commercial Banking | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 369 354    
Commercial Banking | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses (54) (21)    
Commercial Banking | Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 850 875 995 976
Other | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 1 1    
Other | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 0 0    
Other | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 0 0    
Other | Total ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses £ 1 £ 1 £ 1 £ 1