v3.26.1
Allowance for expected credit losses - Schedule of impairment allowances (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 £ 2,662 £ 2,649    
Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 370 355    
Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 140 224    
Total ECL        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 3,172 3,228 £ 3,402 £ 3,481
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        
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        
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        
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 547 555    
Commercial Banking | Individually assessed £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 370 355    
Commercial Banking | Judgemental adjustments £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses (56) (22)    
Commercial Banking | Total ECL        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 861 888 1,009 989
Other | Modelled ECL £m        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses 15 15    
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        
Schedule Of Allowance Account For Credit Losses Of Financial Assets [Line Items]        
Allowance for expected credit losses £ 15 £ 15 £ 15 £ 16