v3.25.2
Fair value of financial instruments - Assets and liabilities held at fair value disaggregated by valuation technique (fair value hierarchy) and balance sheet classification (Details) - GBP (£)
£ in Millions
Jun. 30, 2025
Dec. 31, 2024
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets £ 186,243 £ 166,244
Financial assets at fair value through the income statement 216,633 191,845
Derivative financial instruments 279,671 292,356
Financial assets at fair value through other comprehensive income 46,136 51,010
Trading portfolio liabilities (67,802) (56,182)
Financial liabilities designated at fair value (315,762) (279,777)
Derivative financial instruments (265,289) (279,331)
At fair value    
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets 186,243 166,244
Financial assets at fair value through the income statement 216,633 191,845
Derivative financial instruments 279,671 292,356
Financial assets at fair value through other comprehensive income 46,136 51,010
Investment property 42 9
Total assets 728,725 701,464
Trading portfolio liabilities (67,802) (56,182)
Financial liabilities designated at fair value (315,762) (279,777)
Derivative financial instruments (265,289) (279,331)
Total liabilities (648,853) (615,290)
Quoted market prices (Level 1) | At fair value    
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets 86,649 77,581
Financial assets at fair value through the income statement 7,634 3,463
Derivative financial instruments 108 101
Financial assets at fair value through other comprehensive income 16,589 19,021
Investment property 0 0
Total assets 110,980 100,166
Trading portfolio liabilities (38,150) (27,033)
Financial liabilities designated at fair value (1,576) (181)
Derivative financial instruments (93) (86)
Total liabilities (39,819) (27,300)
Observable inputs (Level 2) | At fair value    
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets 89,715 78,548
Financial assets at fair value through the income statement 202,612 182,391
Derivative financial instruments 277,580 290,182
Financial assets at fair value through other comprehensive income 26,403 28,315
Investment property 0 0
Total assets 596,310 579,436
Trading portfolio liabilities (29,228) (28,754)
Financial liabilities designated at fair value (311,355) (276,355)
Derivative financial instruments (262,335) (276,064)
Total liabilities (602,918) (581,173)
Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets 9,879 10,115
Financial assets at fair value through the income statement 6,387 5,991
Derivative financial instruments 1,983 2,073
Financial assets at fair value through other comprehensive income 3,144 3,674
Investment property 42 9
Total assets 21,435 21,862
Trading portfolio liabilities (424) (395)
Financial liabilities designated at fair value (2,831) (3,241)
Derivative financial instruments (2,861) (3,181)
Total liabilities (6,116) (6,817)
Significant unobservable inputs (Level 3) | At fair value    
Disclosure of detailed information about financial instruments [line items]    
Trading portfolio assets 9,879 10,115
Financial assets at fair value through the income statement 6,387 5,991
Derivative financial instruments 1,983 2,073
Financial assets at fair value through other comprehensive income 3,144 3,674
Investment property 42 9
Total assets 21,435 21,862
Trading portfolio liabilities (424) (395)
Financial liabilities designated at fair value (2,831) (3,241)
Derivative financial instruments (2,861) (3,181)
Total liabilities £ (6,116) £ (6,817)