v3.25.2
Credit Risk - Narrative (Details)
£ in Millions
 6 Months Ended
Jun. 30, 2025
GBP (£)
economic_scenario
Dec. 31, 2024
GBP (£)
Disclosure of financial assets [line items]    
Expected credit loss rate 100.00%  
Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (5,395) £ (5,532)
Credit risk    
Disclosure of financial assets [line items]    
Number of economic scenarios | economic_scenario 5  
Stress horizon period, ECL 5 years  
Baseline    
Disclosure of financial assets [line items]    
Weighted expected credit loss, uplift percentage 1.60%  
Total weighted model ECL | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (4,499) (4,737)
Post-model adjustment, net of significant risk transfer | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (70)  
Loans and advances | Total weighted model ECL | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (4,500) (4,700)
Loans and advances | Financial assets at amortised cost    
Disclosure of financial assets [line items]    
Financial assets 347,828 346,273
Loans and advances | Financial assets at amortised cost | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (4,946) (5,070)
Loans and advances | Financial assets at amortised cost | Total weighted model ECL | Credit risk | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (4,499) (4,737)
Loans and advances | Financial assets at amortised cost | Total weighted model ECL | Baseline | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (4,426) (4,675)
Loans and advances | Financial assets at amortised cost | Total weighted model ECL | Downside 2 | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (5,516) (5,713)
Retail mortgages | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (180) (187)
Retail mortgages | Baseline    
Disclosure of financial assets [line items]    
Weighted expected credit loss, uplift percentage 21.10%  
Retail mortgages | Financial assets at amortised cost    
Disclosure of financial assets [line items]    
Financial assets £ 171,790 168,061
Retail mortgages | Financial assets at amortised cost | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (180) (187)
Retail mortgages | Financial assets at amortised cost | Total weighted model ECL | Credit risk | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (23) (24)
Retail mortgages | Financial assets at amortised cost | Total weighted model ECL | Baseline | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (19) (21)
Retail mortgages | Financial assets at amortised cost | Total weighted model ECL | Downside 2 | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (49) (63)
Retail credit cards | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (3,108) (3,307)
Retail credit cards | Financial assets at amortised cost    
Disclosure of financial assets [line items]    
Financial assets 33,600 34,779
Retail credit cards | Financial assets at amortised cost | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (3,108) (3,307)
Retail credit cards | Financial assets at amortised cost | Total weighted model ECL | Credit risk | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (3,392) (3,633)
Retail credit cards | Financial assets at amortised cost | Total weighted model ECL | Baseline | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (3,377) (3,620)
Retail credit cards | Financial assets at amortised cost | Total weighted model ECL | Downside 2 | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (3,721) (3,995)
Retail other | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (455) (410)
Retail other | Baseline    
Disclosure of financial assets [line items]    
Weighted expected credit loss, uplift percentage 3.40%  
Retail other | Financial assets at amortised cost    
Disclosure of financial assets [line items]    
Financial assets £ 13,806 13,808
Retail other | Financial assets at amortised cost | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (455) (410)
Retail other | Financial assets at amortised cost | Total weighted model ECL | Credit risk | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (185) (207)
Retail other | Financial assets at amortised cost | Total weighted model ECL | Baseline | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (179) (202)
Retail other | Financial assets at amortised cost | Total weighted model ECL | Downside 2 | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (244) (271)
Corporate loans | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (1,203) (1,166)
Corporate loans | Baseline    
Disclosure of financial assets [line items]    
Weighted expected credit loss, uplift percentage 5.60%  
Corporate loans | Financial assets at amortised cost    
Disclosure of financial assets [line items]    
Financial assets £ 128,632 129,625
Corporate loans | Financial assets at amortised cost | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (1,203) (1,166)
Corporate loans | Financial assets at amortised cost | Total weighted model ECL | Credit risk | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (899) (873)
Corporate loans | Financial assets at amortised cost | Total weighted model ECL | Baseline | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets (851) (832)
Corporate loans | Financial assets at amortised cost | Total weighted model ECL | Downside 2 | Impairment allowance    
Disclosure of financial assets [line items]    
Financial assets £ (1,502) £ (1,384)