v3.26.1
Credit risk - Loans and advances at amortised cost by product (Details)
£ in Millions
Jun. 30, 2026
GBP (£)
Dec. 31, 2025
GBP (£)
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Provisions £ 723 £ 766
Expected credit losses held against contingent liabilities and commitments    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Provisions 410 398
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 213,009 £ 205,939
Coverage ratio 0.018 0.017
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 198,781 £ 193,131
Coverage ratio 0.003 0.003
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 11,693 £ 10,419
Coverage ratio 0.082 0.091
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 11,036 £ 9,709
Coverage ratio 0.066 0.071
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 297 £ 310
Coverage ratio 0.268 0.265
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 360 £ 400
Coverage ratio 0.300 0.327
Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 2,535 £ 2,389
Coverage ratio 0.465 0.459
Total loans and advances at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 156,430 £ 150,786
Coverage ratio 0.024 0.023
Total loans and advances at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 143,369 £ 138,340
Coverage ratio 0.004 0.004
Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 10,526 £ 10,057
Coverage ratio 0.089 0.093
Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 9,869 £ 9,347
Coverage ratio 0.072 0.072
Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 297 £ 310
Coverage ratio 0.268 0.265
Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 360 £ 400
Coverage ratio 0.300 0.327
Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 2,535 £ 2,389
Coverage ratio 0.465 0.459
Retail mortgages | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 4,837 £ 4,952
Coverage ratio 0.008 0.007
Retail mortgages | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 4,358 £ 4,665
Coverage ratio 0.002 0.002
Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 278 £ 136
Coverage ratio 0.004 0
Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 211 £ 34
Coverage ratio 0.005 0
Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1 £ 1
Coverage ratio 0 0
Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 66 £ 101
Coverage ratio 0 0
Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 201 £ 151
Coverage ratio 0.122 0.137
Retail credit cards | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 20,988 £ 20,527
Coverage ratio 0.112 0.112
Retail credit cards | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 18,629 £ 18,406
Coverage ratio 0.022 0.021
Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1,995 £ 1,740
Coverage ratio 0.282 0.314
Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1,794 £ 1,514
Coverage ratio 0.232 0.251
Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 131 £ 133
Coverage ratio 0.430 0.441
Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 70 £ 93
Coverage ratio 0.674 0.663
Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 364 £ 381
Coverage ratio 0.799 0.785
Retail other | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 4,557 £ 4,128
Coverage ratio 0.007 0.008
Retail other | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 3,904 £ 3,781
Coverage ratio 0.002 0.002
Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 504 £ 260
Coverage ratio 0.012 0.019
Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 331 £ 77
Coverage ratio 0.012 0.038
Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 90 £ 122
Coverage ratio 0.011 0.008
Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 83 £ 61
Coverage ratio 0.012 0.016
Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 149 £ 87
Coverage ratio 0.108 0.187
Corporate loans | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 126,048 £ 121,179
Coverage ratio 0.009 0.008
Corporate loans | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 116,478 £ 111,488
Coverage ratio 0.001 0.001
Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 7,749 £ 7,921
Coverage ratio 0.030 0.029
Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 7,533 £ 7,722
Coverage ratio 0.029 0.028
Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 75 £ 54
Coverage ratio 0.107 0.100
Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 141 £ 145
Coverage ratio 0.054 0.065
Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1,821 £ 1,770
Coverage ratio 0.279 0.250
Debt securities at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 56,579 £ 55,153
Coverage ratio 0 0
Debt securities at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 55,412 £ 54,791
Coverage ratio 0 0
Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1,167 £ 362
Coverage ratio 0.008 0.024
Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 1,167 £ 362
Coverage ratio 0.008 0.024
Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 0 £ 0
Coverage ratio 0 0
Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 0 £ 0
Coverage ratio 0 0
Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 0 £ 0
Coverage ratio 0 0
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ 216,829 £ 209,575
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 199,360 193,693
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 12,733 11,464
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 11,813 10,448
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 406 422
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 514 594
Gross exposure | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,736 4,418
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 160,234 154,403
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 143,941 138,892
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 11,557 11,093
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 10,637 10,077
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 406 422
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 514 594
Gross exposure | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,736 4,418
Gross exposure | Retail mortgages    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,874 4,985
Gross exposure | Retail mortgages | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,366 4,674
Gross exposure | Retail mortgages | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 279 136
Gross exposure | Retail mortgages | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 229 175
Gross exposure | Retail mortgages | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,874 4,985
Gross exposure | Retail mortgages | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,366 4,674
Gross exposure | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 279 136
Gross exposure | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 212 34
Gross exposure | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 1 1
Gross exposure | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 66 101
Gross exposure | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 229 175
Gross exposure | Retail credit cards    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 23,635 23,113
Gross exposure | Retail credit cards | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 19,041 18,801
Gross exposure | Retail credit cards | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 2,780 2,536
Gross exposure | Retail credit cards | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 1,814 1,776
Gross exposure | Retail credit cards | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 23,635 23,113
Gross exposure | Retail credit cards | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 19,041 18,801
Gross exposure | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 2,780 2,536
Gross exposure | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 2,335 2,022
Gross exposure | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 230 238
Gross exposure | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 215 276
Gross exposure | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 1,814 1,776
Gross exposure | Retail other    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,589 4,160
Gross exposure | Retail other | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 3,912 3,788
Gross exposure | Retail other | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 510 265
Gross exposure | Retail other | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 167 107
Gross exposure | Retail other | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 4,589 4,160
Gross exposure | Retail other | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 3,912 3,788
Gross exposure | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 510 265
Gross exposure | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 335 80
Gross exposure | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 91 123
Gross exposure | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 84 62
Gross exposure | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 167 107
Gross exposure | Corporate loans    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 127,136 122,145
Gross exposure | Corporate loans | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 116,622 111,629
Gross exposure | Corporate loans | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 7,988 8,156
Gross exposure | Corporate loans | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 2,526 2,360
Gross exposure | Corporate loans | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 127,136 122,145
Gross exposure | Corporate loans | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 116,622 111,629
Gross exposure | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 7,988 8,156
Gross exposure | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 7,755 7,941
Gross exposure | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 84 60
Gross exposure | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 149 155
Gross exposure | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 2,526 2,360
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 56,595 55,172
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 55,419 54,801
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 1,176 371
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 1,176 371
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Gross exposure | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Gross exposure | Other financial assets subject to impairment    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 246,100 186,100
Gross exposure | Other financial assets subject to impairment | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 245,200 184,400
Gross exposure | Other financial assets subject to impairment | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 800 1,600
Gross exposure | Other financial assets subject to impairment | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 124 123
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (3,820) (3,636)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (579) (562)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,040) (1,045)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (777) (739)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (109) (112)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (154) (194)
Impairment allowance | Total loans and advances at amortised cost including debt securities | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (2,201) (2,029)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (3,804) (3,617)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (572) (552)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,031) (1,036)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (768) (730)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (109) (112)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (154) (194)
Impairment allowance | Total loans and advances at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (2,201) (2,029)
Impairment allowance | Retail mortgages    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (37) (33)
Impairment allowance | Retail mortgages | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (8) (9)
Impairment allowance | Retail mortgages | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1) 0
Impairment allowance | Retail mortgages | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (28) (24)
Impairment allowance | Retail mortgages | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (37) (33)
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (8) (9)
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1) 0
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1) 0
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Impairment allowance | Retail mortgages | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (28) (24)
Impairment allowance | Retail credit cards    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (2,647) (2,586)
Impairment allowance | Retail credit cards | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (412) (395)
Impairment allowance | Retail credit cards | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (785) (796)
Impairment allowance | Retail credit cards | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,450) (1,395)
Impairment allowance | Retail credit cards | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (2,647) (2,586)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (412) (395)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (785) (796)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (541) (508)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (99) (105)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (145) (183)
Impairment allowance | Retail credit cards | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,450) (1,395)
Impairment allowance | Retail other    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (32) (32)
Impairment allowance | Retail other | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (8) (7)
Impairment allowance | Retail other | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (6) (5)
Impairment allowance | Retail other | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (18) (20)
Impairment allowance | Retail other | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (32) (32)
Impairment allowance | Retail other | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (8) (7)
Impairment allowance | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (6) (5)
Impairment allowance | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (4) (3)
Impairment allowance | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1) (1)
Impairment allowance | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1) (1)
Impairment allowance | Retail other | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (18) (20)
Impairment allowance | Corporate loans    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,088) (966)
Impairment allowance | Corporate loans | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (144) (141)
Impairment allowance | Corporate loans | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (239) (235)
Impairment allowance | Corporate loans | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (705) (590)
Impairment allowance | Corporate loans | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (1,088) (966)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (144) (141)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (239) (235)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (222) (219)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (9) (6)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (8) (10)
Impairment allowance | Corporate loans | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (705) (590)
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (16) (19)
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (7) (10)
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (9) (9)
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (9) (9)
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | Not later than 30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 2 | >30 days past due    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Impairment allowance | Debt securities at amortised cost | Financial assets at amortised cost | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets 0 0
Impairment allowance | Other financial assets subject to impairment    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (147) (145)
Impairment allowance | Other financial assets subject to impairment | Stage 1    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (16) (17)
Impairment allowance | Other financial assets subject to impairment | Lifetime expected credit losses | Stage 2    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets (10) (8)
Impairment allowance | Other financial assets subject to impairment | Lifetime expected credit losses | Stage 3    
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]    
Financial assets £ (121) £ (120)