v3.26.1
Credit Risk - Disclosure of management adjustments to models for impairment and Economic uncertainty management adjustments to models for impairment presented by stage (Details) - GBP (£)
£ in Millions
Jun. 30, 2026
Dec. 31, 2025
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 4.80% 6.40%
Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 5,969 £ 5,727
Impairment allowance | American Airlines Portfolio | Assets and liabilities classified as held for sale    
Disclosure of financial assets [line items]    
Financial assets 0 200
Total impairment allowance | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 5,969 5,727
Impairment allowance pre management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 5,680 5,358
Modelled ECL | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 4,328 4,358
Individually assessed impairments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 882 672
Management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 289 369
Economic uncertainty adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 76 115
Other adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 213 £ 254
Loans and advances    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 4.80% 6.50%
Loans and advances | UK    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 6.90% 8.90%
Loans and advances | Rest of the world    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 3.40% 4.90%
Loans and advances | Total impairment allowance | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 5,949 £ 5,705
Loans and advances | Total impairment allowance | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2,417 2,149
Loans and advances | Total impairment allowance | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 3,532 3,556
Loans and advances | Impairment allowance pre management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 5,662 5,337
Loans and advances | Impairment allowance pre management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2,250 1,957
Loans and advances | Impairment allowance pre management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 3,412 3,380
Loans and advances | Modelled ECL | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 4,300 4,300
Loans and advances | Individually assessed impairments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 900 700
Loans and advances | ECL from non-modelled exposures and debt securities | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 500 600
Loans and advances | Management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 287 368
Loans and advances | Management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 167 192
Loans and advances | Management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 120 176
Loans and advances | Economic uncertainty adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 74 114
Loans and advances | Economic uncertainty adjustments | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 25 36
Loans and advances | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 48 72
Loans and advances | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 1 6
Loans and advances | Economic uncertainty adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 17 39
Loans and advances | Economic uncertainty adjustments | UK | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 9 23
Loans and advances | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 7 10
Loans and advances | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 1 6
Loans and advances | Economic uncertainty adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 57 75
Loans and advances | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 16 13
Loans and advances | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 41 62
Loans and advances | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Loans and advances | Other adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 213 254
Loans and advances | Other adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 150 153
Loans and advances | Other adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 63 101
Retail mortgages | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 127 117
Retail mortgages | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 19 17
Retail mortgages | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets £ 21 £ 16
Retail mortgages | UK    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 4.10% 16.50%
Retail mortgages | Rest of the world    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 0.00% 3.80%
Retail mortgages | Total impairment allowance | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 97 £ 91
Retail mortgages | Total impairment allowance | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 30 26
Retail mortgages | Impairment allowance pre management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 93 76
Retail mortgages | Impairment allowance pre management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 30 25
Retail mortgages | Management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 4 15
Retail mortgages | Management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 1
Retail mortgages | Economic uncertainty adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | UK | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail mortgages | Other adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 4 15
Retail mortgages | Other adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 1
Retail credit cards | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 3,436 3,329
Retail credit cards | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 582 566
Retail credit cards | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets £ 1,215 £ 1,194
Retail credit cards | UK    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 0.00% 0.00%
Retail credit cards | Rest of the world    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 2.00% 4.50%
Retail credit cards | Total impairment allowance | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 812 £ 761
Retail credit cards | Total impairment allowance | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2,690 2,623
Retail credit cards | Impairment allowance pre management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 812 761
Retail credit cards | Impairment allowance pre management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2,635 2,505
Retail credit cards | Management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 55 118
Retail credit cards | Economic uncertainty adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | UK | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 31
Retail credit cards | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 31
Retail credit cards | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 0 31
Retail credit cards | Other adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail credit cards | Other adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 55 87
Retail other | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 536 517
Retail other | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 110 101
Retail other | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets £ 190 £ 183
Retail other | UK    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 19.20% 17.30%
Retail other | Rest of the world    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 6.50% 0.00%
Retail other | Total impairment allowance | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 506 £ 491
Retail other | Total impairment allowance | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 31 27
Retail other | Impairment allowance pre management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 409 406
Retail other | Impairment allowance pre management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 29 27
Retail other | Management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 97 85
Retail other | Management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2 0
Retail other | Economic uncertainty adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | UK | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Retail other | Other adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 97 85
Retail other | Other adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2 0
Corporate loans | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 1,417 1,326
Corporate loans | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 189 207
Corporate loans | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets £ 315 £ 315
Corporate loans | UK    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 6.60% 11.40%
Corporate loans | Rest of the world    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 8.10% 6.50%
Corporate loans | Total impairment allowance | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 1,002 £ 806
Corporate loans | Total impairment allowance | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 781 880
Corporate loans | Impairment allowance pre management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 936 714
Corporate loans | Impairment allowance pre management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 718 823
Corporate loans | Management adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 66 92
Corporate loans | Management adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 63 57
Corporate loans | Economic uncertainty adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 17 39
Corporate loans | Economic uncertainty adjustments | UK | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 9 23
Corporate loans | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 7 10
Corporate loans | Economic uncertainty adjustments | UK | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 1 6
Corporate loans | Economic uncertainty adjustments | UK | Impairment allowance | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 17 39
Corporate loans | Economic uncertainty adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 57 44
Corporate loans | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 16 13
Corporate loans | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 41 31
Corporate loans | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Corporate loans | Economic uncertainty adjustments | Rest of the world | Impairment allowance | Cross default risk    
Disclosure of financial assets [line items]    
Financial assets 57 44
Corporate loans | Other adjustments | UK | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 49 53
Corporate loans | Other adjustments | Rest of the world | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 6 £ 13
Debt securities at amortised cost    
Disclosure of financial assets [line items]    
Proportion of Management adjustments to total impairment allowance 10.00% 4.50%
Debt securities at amortised cost | Total impairment allowance | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ 20 £ 22
Debt securities at amortised cost | Impairment allowance pre management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 18 21
Debt securities at amortised cost | Management adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2 1
Debt securities at amortised cost | Economic uncertainty adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 2 1
Debt securities at amortised cost | Economic uncertainty adjustments | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 1 1
Debt securities at amortised cost | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 1 0
Debt securities at amortised cost | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 0 0
Debt securities at amortised cost | Other adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 0 0
Loans and advances at amortised cost including debt securities    
Disclosure of financial assets [line items]    
Financial assets (444,820) (429,998)
Loans and advances at amortised cost including debt securities | Stage 1    
Disclosure of financial assets [line items]    
Financial assets (409,180) (395,801)
Loans and advances at amortised cost including debt securities | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets (30,821) (29,318)
Loans and advances at amortised cost including debt securities | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 5,536 5,311
Loans and advances at amortised cost including debt securities | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 911 904
Loans and advances at amortised cost including debt securities | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 1,750 1,717
Loans and advances at amortised cost including debt securities | Economic uncertainty adjustments | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets 76 115
Loans and advances at amortised cost including debt securities | Economic uncertainty adjustments | Impairment allowance | Stage 1    
Disclosure of financial assets [line items]    
Financial assets 26 37
Loans and advances at amortised cost including debt securities | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 2    
Disclosure of financial assets [line items]    
Financial assets 49 72
Loans and advances at amortised cost including debt securities | Economic uncertainty adjustments | Impairment allowance | Lifetime expected credit losses | Stage 3    
Disclosure of financial assets [line items]    
Financial assets 1 6
Cash collateral and settlements | Management adjustments | Impairment allowance | Other financial assets subject to impairment | Barclays Investment Bank    
Disclosure of financial assets [line items]    
Financial assets 1 1
Reverse repurchase agreements | Management adjustments | Impairment allowance | Other financial assets subject to impairment | Barclays Investment Bank    
Disclosure of financial assets [line items]    
Financial assets £ 1 £ 1