v3.26.1
Credit Risk - Economic uncertainty adjustments and Other adjustments (Narrative) (Details) - GBP (£)
£ in Millions
Jun. 30, 2026
Dec. 31, 2025
Loans and advances at amortised cost including debt securities    
Disclosure of financial assets [line items]    
Financial assets £ (444,820) £ (429,998)
Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 5,969 5,727
Impairment allowance | Loans and advances at amortised cost including debt securities    
Disclosure of financial assets [line items]    
Financial assets 5,536 5,311
Impairment allowance | Retail mortgages    
Disclosure of financial assets [line items]    
Financial assets 127 117
Impairment allowance | Retail credit cards    
Disclosure of financial assets [line items]    
Financial assets 3,436 3,329
Impairment allowance | Corporate loans    
Disclosure of financial assets [line items]    
Financial assets 1,417 1,326
Impairment allowance | Retail other    
Disclosure of financial assets [line items]    
Financial assets 536 517
Impairment allowance | Post-model adjustment    
Disclosure of financial assets [line items]    
Financial assets 66  
Impairment allowance | Economic uncertainty adjustments    
Disclosure of financial assets [line items]    
Financial assets 76 115
Impairment allowance | Economic uncertainty adjustments | Loans and advances at amortised cost including debt securities    
Disclosure of financial assets [line items]    
Financial assets 76 115
Impairment allowance | Economic uncertainty adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 74 114
Impairment allowance | Other adjustments    
Disclosure of financial assets [line items]    
Financial assets 213 254
Impairment allowance | Other adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 213 254
Impairment allowance | UK | Economic uncertainty adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 17 39
Impairment allowance | UK | Economic uncertainty adjustments | Retail mortgages    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | UK | Economic uncertainty adjustments | Retail credit cards    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | UK | Economic uncertainty adjustments | Corporate loans    
Disclosure of financial assets [line items]    
Financial assets 17 39
Impairment allowance | UK | Economic uncertainty adjustments | Corporate loans | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 17 39
Impairment allowance | UK | Economic uncertainty adjustments | Retail other    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | UK | Other adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 150 153
Impairment allowance | UK | Other adjustments | Retail mortgages    
Disclosure of financial assets [line items]    
Financial assets 4 15
Impairment allowance | UK | Other adjustments | Retail credit cards    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | UK | Other adjustments | Corporate loans    
Disclosure of financial assets [line items]    
Financial assets 49 53
Impairment allowance | UK | Other adjustments | Retail other    
Disclosure of financial assets [line items]    
Financial assets 97 85
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 57 75
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Retail mortgages    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Retail credit cards    
Disclosure of financial assets [line items]    
Financial assets 0 31
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Retail credit cards | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 0 31
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Corporate loans    
Disclosure of financial assets [line items]    
Financial assets 57 44
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Corporate loans | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 57 44
Impairment allowance | Rest of the world | Economic uncertainty adjustments | Retail other    
Disclosure of financial assets [line items]    
Financial assets 0 0
Impairment allowance | Rest of the world | Other adjustments | Loans and advances    
Disclosure of financial assets [line items]    
Financial assets 63 101
Impairment allowance | Rest of the world | Other adjustments | Retail mortgages    
Disclosure of financial assets [line items]    
Financial assets 0 1
Impairment allowance | Rest of the world | Other adjustments | Retail credit cards    
Disclosure of financial assets [line items]    
Financial assets 55 87
Impairment allowance | Rest of the world | Other adjustments | Corporate loans    
Disclosure of financial assets [line items]    
Financial assets 6 13
Impairment allowance | Rest of the world | Other adjustments | Retail other    
Disclosure of financial assets [line items]    
Financial assets £ 2 £ 0