v3.25.2
Report Of The Directors Financial Review Risk Report - Reconciliation of changes in gross carrying/nominal amount and allowances for loans and advances to banks and customers including loan commitments and financial guarantees (Details)
£ in Millions, $ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2025
USD ($)
Jun. 30, 2025
GBP (£)
Dec. 31, 2024
USD ($)
Jun. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance $ 153,973.0        
Financial assets, ending balance 166,209.0   $ 153,973.0   $ 153,973.0
Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 353,855.0        
Financial assets, ending balance 402,487.0   353,855.0   353,855.0
Financial instruments including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Total ECL income statement change for the period (1,941.0)       (3,414.0)
Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
ECL income statement change for the period (1,951.0)        
Total ECL income statement change for the period (1,956.0)       (3,133.0)
Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 828,488.0        
Financial assets, ending balance 890,508.0   828,488.0   828,488.0
Debt securities in issue | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 131,825.0        
Financial assets, ending balance 144,966.0   131,825.0   131,825.0
Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Total ECL income statement change for the period (3.0)       6.0
Loans and advances to customers          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 930,658.0        
Financial assets, ending balance 981,722.0   930,658.0   930,658.0
Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 930,658.0        
Financial assets, ending balance 981,722.0   930,658.0   930,658.0
Loans and advances to banks          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 102,039.0        
Financial assets, ending balance 107,582.0   102,039.0   102,039.0
Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 102,039.0        
Financial assets, ending balance 107,582.0   102,039.0   102,039.0
IFRS 9 | Financial instruments including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Total ECL income statement change for the period (1,938.0)       (3,420.0)
IFRS 9 | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Total ECL income statement change for the period (31.0)       (114.0)
IFRS 9 | Performance and other guarantees not considered for IFRS 9          
Increase (decrease) in financial assets [abstract]          
Total ECL income statement change for the period 49.0       (173.0)
Stage 1 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
ECL income statement change for the period 415.0        
Stage 1 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 826,557.0        
Financial assets, ending balance 888,349.0   826,557.0   826,557.0
Stage 1 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 352,971.0        
Financial assets, ending balance 401,360.0   352,971.0   352,971.0
Stage 1 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 823,342.0        
Financial assets, ending balance 851,488.0   823,342.0   823,342.0
Stage 1 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 101,843.0        
Financial assets, ending balance 107,418.0   101,843.0   101,843.0
Stage 2 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
ECL income statement change for the period (1,001.0)        
Stage 2 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,801.0        
Financial assets, ending balance 1,994.0   1,801.0   1,801.0
Stage 2 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 884.0        
Financial assets, ending balance 1,101.0   884.0   884.0
Stage 2 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 90,702.0        
Financial assets, ending balance 112,586.0   90,702.0   90,702.0
Stage 2 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 196.0        
Financial assets, ending balance 164.0   196.0   196.0
Stage 2 | Credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
ECL income statement change for the period (1,352.0)        
Stage 2 | Credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 130.0        
Financial assets, ending balance 165.0   130.0   130.0
Stage 2 | Credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 26.0   0.0   0.0
Stage 2 | Credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 16,575.0        
Financial assets, ending balance 17,406.0   16,575.0   16,575.0
Stage 2 | Credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Stage 2 | – POCI | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
ECL income statement change for the period (13.0)        
Stage 2 | – POCI | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Stage 2 | – POCI | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Stage 2 | – POCI | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 39.0        
Financial assets, ending balance 242.0   39.0   39.0
Stage 2 | – POCI | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Gross carrying amount | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,958,010.0        
Financial assets, ending balance 2,007,707.0   1,958,010.0   1,958,010.0
Gross carrying amount | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 2,507,370.0        
Financial assets, ending balance 2,698,402.0   2,507,370.0   2,507,370.0
Gross carrying amount | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 353,909.0        
Financial assets, ending balance 402,550.0   353,909.0   353,909.0
Gross carrying amount | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,629,501.0     $ 1,670,773.0 1,670,773.0
Changes due to modifications not derecognised (7.0)       (25.0)
Net new and further lending/ repayments 20,479.0       44,863.0
Assets written off (2,029.0)       (4,459.0)
Credit-related modifications that resulted in derecognition | £   £ (88)      
Foreign exchange and others 64,959.0       (81,651.0)
Financial assets, ending balance 1,712,815.0   1,629,501.0   1,629,501.0
Gross carrying amount | Loans and advances to bank and customers including loan commitments and financial guarantees | Argentina business          
Increase (decrease) in financial assets [abstract]          
Foreign exchange and others         2,700.0
Gross carrying amount | Loans and advances to bank and customers including loan commitments and financial guarantees | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Other (1,300.0)       (3,700.0)
Gross carrying amount | Loans and advances to bank and customers including loan commitments and financial guarantees | Assets held for sale | Banking business in Canada          
Increase (decrease) in financial assets [abstract]          
Other         (35,300.0)
Gross carrying amount | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 828,580.0        
Financial assets, ending balance 890,630.0   828,580.0   828,580.0
Gross carrying amount | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 346,124.0        
Financial assets, ending balance 395,908.0   346,124.0   346,124.0
Gross carrying amount | Loans and advances to customers | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Other (7,200.0)        
Gross carrying amount | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 940,373.0        
Financial assets, ending balance 991,865.0   940,373.0   940,373.0
Gross carrying amount | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 102,052.0        
Financial assets, ending balance 107,597.0   102,052.0   102,052.0
Gross carrying amount | IFRS 9 | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,871,005.0        
Financial assets, ending balance 1,990,092.0   1,871,005.0   1,871,005.0
Gross carrying amount | IFRS 9 | Financial assets at amortised cost, category | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 3,273.0        
Financial assets, ending balance 5,080.0   3,273.0   3,273.0
Gross carrying amount | IFRS 9 | Financial instruments including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 2,507,370.0        
Financial assets, ending balance 2,698,402.0   2,507,370.0   2,507,370.0
Gross carrying amount | IFRS 9 | Non-trading reverse purchase agreement commitments          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 49,289.0        
Financial assets, ending balance 94,957.0   49,289.0   49,289.0
Gross carrying amount | IFRS 9 | Non-trading reverse purchase agreement commitments | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 252,549.0        
Financial assets, ending balance 283,204.0   252,549.0   252,549.0
Gross carrying amount | IFRS 9 | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 828,580.0        
Financial assets, ending balance 890,630.0   828,580.0   828,580.0
Gross carrying amount | IFRS 9 | Other financial assets measured at amortised cost | Financial assets at amortised cost, category | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 2,100.0        
Financial assets, ending balance 2,800.0   2,100.0   2,100.0
Gross carrying amount | IFRS 9 | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 940,373.0        
Financial assets, ending balance 991,865.0   940,373.0   940,373.0
Gross carrying amount | IFRS 9 | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 102,052.0        
Financial assets, ending balance 107,597.0   102,052.0   102,052.0
Gross carrying amount | Stage 1 | Non-credit impaired | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,830,264.0        
Financial assets, ending balance 1,838,904.0   1,830,264.0   1,830,264.0
Gross carrying amount | Stage 1 | Non-credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 2,365,477.0        
Financial assets, ending balance 2,531,205.0   2,365,477.0   2,365,477.0
Gross carrying amount | Stage 1 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,489,687.0     1,496,805.0 1,496,805.0
Transfers of financial instruments: (44,123.0)       (19,629.0)
– transfers from stage 1 to stage 2 (82,621.0)       (116,211.0)
– transfers from stage 2 to stage 1 39,013.0       98,731.0
– transfers to stage 3 (693.0)       (2,799.0)
– transfers from stage 3 178.0       650.0
Net new and further lending/ repayments 44,603.0       87,833.0
Foreign exchange and others 57,658.0       (75,322.0)
Financial assets, ending balance 1,547,825.0   1,489,687.0   1,489,687.0
Gross carrying amount | Stage 1 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 826,621.0        
Financial assets, ending balance 888,423.0   826,621.0   826,621.0
Gross carrying amount | Stage 1 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 353,002.0        
Financial assets, ending balance 401,397.0   353,002.0   353,002.0
Gross carrying amount | Stage 1 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 824,420.0        
Financial assets, ending balance 852,669.0   824,420.0   824,420.0
Gross carrying amount | Stage 1 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 101,852.0        
Financial assets, ending balance 107,428.0   101,852.0   101,852.0
Gross carrying amount | Stage 2 | Non-credit impaired | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 127,746.0        
Financial assets, ending balance 168,803.0   127,746.0   127,746.0
Gross carrying amount | Stage 2 | Non-credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 117,824.0        
Financial assets, ending balance 141,777.0   117,824.0   117,824.0
Gross carrying amount | Stage 2 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 115,898.0     153,084.0 153,084.0
Transfers of financial instruments: 39,727.0       6,652.0
– transfers from stage 1 to stage 2 82,621.0       116,211.0
– transfers from stage 2 to stage 1 (39,013.0)       (98,731.0)
– transfers to stage 3 (4,617.0)       (12,230.0)
– transfers from stage 3 736.0       1,402.0
Net new and further lending/ repayments (22,112.0)       (37,731.0)
Foreign exchange and others 6,253.0       (6,107.0)
Financial assets, ending balance 139,766.0   115,898.0   115,898.0
Gross carrying amount | Stage 2 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 1,806.0        
Financial assets, ending balance 2,011.0   1,806.0   1,806.0
Gross carrying amount | Stage 2 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 907.0        
Financial assets, ending balance 1,122.0   907.0   907.0
Gross carrying amount | Stage 2 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 93,248.0        
Financial assets, ending balance 115,338.0   93,248.0   93,248.0
Gross carrying amount | Stage 2 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 198.0        
Financial assets, ending balance 166.0   198.0   198.0
Gross carrying amount | Stage 2 | Credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 23,976.0        
Financial assets, ending balance 25,108.0   23,976.0   23,976.0
Gross carrying amount | Stage 2 | Credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 23,823.0     20,799.0 20,799.0
Transfers of financial instruments: 4,396.0       12,977.0
– transfers to stage 3 5,310.0       15,029.0
– transfers from stage 3 (914.0)       (2,052.0)
Changes due to modifications not derecognised (7.0)       (25.0)
Net new and further lending/ repayments (2,225.0)       (5,246.0)
Assets written off (2,029.0)       (4,459.0)
Credit-related modifications that resulted in derecognition | £   (88)      
Foreign exchange and others 1,042.0       (223.0)
Financial assets, ending balance 24,912.0   23,823.0   23,823.0
Gross carrying amount | Stage 2 | Credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 153.0        
Financial assets, ending balance 196.0   153.0   153.0
Gross carrying amount | Stage 2 | Credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 31.0   0.0   0.0
Gross carrying amount | Stage 2 | Credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 22,615.0        
Financial assets, ending balance 23,550.0   22,615.0   22,615.0
Gross carrying amount | Stage 2 | Credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 2.0        
Financial assets, ending balance 3.0   2.0   2.0
Gross carrying amount | Stage 2 | – POCI | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 93.0        
Financial assets, ending balance 312.0   93.0   93.0
Gross carrying amount | Stage 2 | – POCI | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 93.0     85.0 85.0
Net new and further lending/ repayments 213.0       7.0
Foreign exchange and others 6.0       1.0
Financial assets, ending balance 312.0   93.0   93.0
Gross carrying amount | Stage 2 | – POCI | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Gross carrying amount | Stage 2 | – POCI | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Gross carrying amount | Stage 2 | – POCI | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 90.0        
Financial assets, ending balance 308.0   90.0   90.0
Gross carrying amount | Stage 2 | – POCI | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Allowance for ECL          
Increase (decrease) in financial assets [abstract]          
Increase (decrease) in financial assets (5,200.0)       (4,800.0)
Allowance for ECL | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2,205.0)        
Financial assets, ending balance (2,423.0)   (2,205.0)   (2,205.0)
Increase (decrease) in financial assets (2,400.0)       (2,200.0)
Allowance for ECL | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (10,197.0)        
Financial assets, ending balance (10,676.0)   (10,197.0)   (10,197.0)
Allowance for ECL | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (54.0)        
Financial assets, ending balance (63.0)   (54.0)   (54.0)
Allowance for ECL | Financial instruments including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (10,251.0)        
Financial assets, ending balance (10,739.0)   (10,251.0)   (10,251.0)
Allowance for ECL | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (10,105.0)     (11,495.0) (11,495.0)
Net remeasurement of ECL arising from transfer of stage 0.0       (16.0)
Net new and further lending/ repayments 930.0       2,103.0
Changes to risk parameters – credit quality (3,044.0)       (5,366.0)
Changes to models used for ECL calculation (163.0)       44.0
Assets written off 2,029.0       4,459.0
Credit-related modifications that resulted in derecognition   9     0.0
Foreign exchange and others (536.0)       166.0
Financial assets, ending balance (10,554.0)   (10,105.0)   (10,105.0)
ECL income statement change for the period         (3,235.0)
Recoveries 136.0       260.0
Other (141.0)       (158.0)
Total ECL income statement change for the period     2,251.0 882.0  
Increase (decrease) in financial assets 449.0        
Allowance for ECL | Loans and advances to bank and customers including loan commitments and financial guarantees | Wholesale          
Increase (decrease) in financial assets [abstract]          
Assets written off 1,227.0        
Allowance for ECL | Loans and advances to bank and customers including loan commitments and financial guarantees | Personal          
Increase (decrease) in financial assets [abstract]          
Assets written off 802.0        
Allowance for ECL | Loans and advances to bank and customers including loan commitments and financial guarantees | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Other 6.0       46.0
Allowance for ECL | Loans and advances to bank and customers including loan commitments and financial guarantees | Assets held for sale | Banking business in Canada          
Increase (decrease) in financial assets [abstract]          
Other 21.0        
Allowance for ECL | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (92.0)        
Financial assets, ending balance (122.0)   (92.0)   (92.0)
Allowance for ECL | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (54.0)        
Financial assets, ending balance (63.0)   (54.0)   (54.0)
Allowance for ECL | Loans and advances to customers | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Other 7.0        
Allowance for ECL | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (9,715.0)        
Financial assets, ending balance (10,143.0)   (9,715.0)   (9,715.0)
Allowance for ECL | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (13.0)        
Financial assets, ending balance (15.0)   (13.0)   (13.0)
Allowance for ECL | IFRS 9 | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (9,820.0)        
Financial assets, ending balance (10,280.0)   (9,820.0)   (9,820.0)
Allowance for ECL | IFRS 9 | Financial assets at amortised cost, category | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (4.0)        
Financial assets, ending balance (11.0)   (4.0)   (4.0)
Allowance for ECL | IFRS 9 | Financial instruments including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (10,197.0)        
Financial assets, ending balance (10,676.0)   (10,197.0)   (10,197.0)
Allowance for ECL | IFRS 9 | Non-trading reverse purchase agreement commitments | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Allowance for ECL | IFRS 9 | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (92.0)        
Financial assets, ending balance (122.0)   (92.0)   (92.0)
Allowance for ECL | IFRS 9 | Other financial assets measured at amortised cost | Financial assets at amortised cost, category | Assets held for sale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.3        
Financial assets, ending balance 0.2   0.3   0.3
Allowance for ECL | IFRS 9 | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (9,715.0)        
Financial assets, ending balance (10,143.0)   (9,715.0)   (9,715.0)
Allowance for ECL | IFRS 9 | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (13.0)        
Financial assets, ending balance (15.0)   (13.0)   (13.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (689.0)        
Financial assets, ending balance (707.0)   (689.0)   (689.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (1,296.0)        
Financial assets, ending balance (1,418.0)   (1,296.0)   (1,296.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (1,232.0)     (1,300.0) (1,300.0)
Transfers of financial instruments: (459.0)       (1,259.0)
– transfers from stage 1 to stage 2 205.0       419.0
– transfers from stage 2 to stage 1 (639.0)       (1,627.0)
– transfers to stage 3 4.0       16.0
– transfers from stage 3 (29.0)       (67.0)
Net remeasurement of ECL arising from transfer of stage 360.0       959.0
Net new and further lending/ repayments (59.0)       (168.0)
Changes to risk parameters – credit quality 186.0       363.0
Changes to models used for ECL calculation (72.0)       68.0
Foreign exchange and others (68.0)       105.0
Financial assets, ending balance (1,344.0)   (1,232.0)   (1,232.0)
ECL income statement change for the period         1,222.0
Allowance for ECL | Stage 1 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (64.0)        
Financial assets, ending balance (74.0)   (64.0)   (64.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (31.0)        
Financial assets, ending balance (37.0)   (31.0)   (31.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (1,078.0)        
Financial assets, ending balance (1,181.0)   (1,078.0)   (1,078.0)
Allowance for ECL | Stage 1 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (9.0)        
Financial assets, ending balance (10.0)   (9.0)   (9.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Wholesale          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (1,516.0)        
Financial assets, ending balance (1,685.0)   (1,516.0)   (1,516.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2,679.0)        
Financial assets, ending balance (2,898.0)   (2,679.0)   (2,679.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2,674.0)     (3,102.0) (3,102.0)
Transfers of financial instruments: 936.0       2,302.0
– transfers from stage 1 to stage 2 (205.0)       (419.0)
– transfers from stage 2 to stage 1 639.0       1,627.0
– transfers to stage 3 609.0       1,321.0
– transfers from stage 3 (107.0)       (227.0)
Net remeasurement of ECL arising from transfer of stage (341.0)       (831.0)
Net new and further lending/ repayments 317.0       589.0
Changes to risk parameters – credit quality (1,227.0)       (1,773.0)
Changes to models used for ECL calculation 250.0       (4.0)
Foreign exchange and others (142.0)       145.0
Financial assets, ending balance (2,881.0)   (2,674.0)   (2,674.0)
ECL income statement change for the period         (2,019.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (5.0)        
Financial assets, ending balance (17.0)   (5.0)   (5.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (23.0)        
Financial assets, ending balance (21.0)   (23.0)   (23.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2,546.0)        
Financial assets, ending balance (2,752.0)   (2,546.0)   (2,546.0)
Allowance for ECL | Stage 2 | Non-credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2.0)        
Financial assets, ending balance (2.0)   (2.0)   (2.0)
Allowance for ECL | Stage 2 | Credit impaired | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (6,171.0)        
Financial assets, ending balance (6,293.0)   (6,171.0)   (6,171.0)
Allowance for ECL | Stage 2 | Credit impaired | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (6,148.0)     (7,063.0) (7,063.0)
Transfers of financial instruments: (477.0)       (1,043.0)
– transfers to stage 3 (613.0)       (1,337.0)
– transfers from stage 3 136.0       294.0
Net remeasurement of ECL arising from transfer of stage (19.0)       (144.0)
Net new and further lending/ repayments 680.0       1,689.0
Changes to risk parameters – credit quality (1,998.0)       (3,945.0)
Changes to models used for ECL calculation (15.0)       (20.0)
Assets written off 2,029.0       4,459.0
Credit-related modifications that resulted in derecognition | £   £ 9      
Foreign exchange and others (323.0)       (81.0)
Financial assets, ending balance (6,262.0)   (6,148.0)   (6,148.0)
ECL income statement change for the period         (2,420.0)
Allowance for ECL | Stage 2 | Credit impaired | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (23.0)        
Financial assets, ending balance (31.0)   (23.0)   (23.0)
Allowance for ECL | Stage 2 | Credit impaired | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance (5.0)   0.0   0.0
Allowance for ECL | Stage 2 | Credit impaired | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (6,040.0)        
Financial assets, ending balance (6,144.0)   (6,040.0)   (6,040.0)
Allowance for ECL | Stage 2 | Credit impaired | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (2.0)        
Financial assets, ending balance (3.0)   (2.0)   (2.0)
Allowance for ECL | Stage 2 | – POCI | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (51.0)        
Financial assets, ending balance (67.0)   (51.0)   (51.0)
Allowance for ECL | Stage 2 | – POCI | Loans and advances to bank and customers including loan commitments and financial guarantees          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (51.0)     $ (30.0) (30.0)
Net new and further lending/ repayments (8.0)       (7.0)
Changes to risk parameters – credit quality (5.0)       (11.0)
Foreign exchange and others (3.0)       (3.0)
Financial assets, ending balance (67.0)   (51.0)   (51.0)
ECL income statement change for the period         (18.0)
Allowance for ECL | Stage 2 | – POCI | Other financial assets measured at amortised cost | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Allowance for ECL | Stage 2 | – POCI | Debt securities in issue | Debt instruments at FVOCI          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance 0.0   0.0   0.0
Allowance for ECL | Stage 2 | – POCI | Loans and advances to customers | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance (51.0)        
Financial assets, ending balance (66.0)   (51.0)   (51.0)
Allowance for ECL | Stage 2 | – POCI | Loans and advances to banks | Financial assets at amortised cost, category          
Increase (decrease) in financial assets [abstract]          
Financial assets, beginning balance 0.0        
Financial assets, ending balance $ 0.0   $ 0.0   $ 0.0