v3.25.4
Fair value of financial instruments - Disclosure of unrealised gains and losses on Level 3 financial assets and liabilities (Details) - GBP (£)
£ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about financial instruments [line items]      
Trading income £ 7,104 £ 5,900 £ 5,980
Other income 48 52 62
Other comprehensive income 1,099 (1,240) 32
Total trading portfolio assets | Trading portfolio liabilities      
Disclosure of detailed information about financial instruments [line items]      
Trading income 5,160 4,201 £ 4,310
Level 3      
Disclosure of detailed information about financial instruments [line items]      
Trading income 53 (148)  
Other income (23) 77  
Other comprehensive income 0 0  
Total 30 (71)  
Level 3 | Investment property      
Disclosure of detailed information about financial instruments [line items]      
Trading income 0 0  
Other income 0 0  
Other comprehensive income 0 0  
Total 0 0  
Level 3 | Net derivative financial instruments      
Disclosure of detailed information about financial instruments [line items]      
Trading income (44) (58)  
Other income 1 0  
Other comprehensive income 0 0  
Total (43) (58)  
Level 3 | Trading portfolio liabilities      
Disclosure of detailed information about financial instruments [line items]      
Trading income 1 (7)  
Other income 0 0  
Other comprehensive income 0 0  
Total 1 (7)  
Level 3 | Financial liabilities designated at fair value      
Disclosure of detailed information about financial instruments [line items]      
Trading income 43 (77)  
Other income 0 0  
Other comprehensive income 0 0  
Total 43 (77)  
Level 3 | Total trading portfolio assets      
Disclosure of detailed information about financial instruments [line items]      
Trading income 36 (9)  
Other income 0 0  
Other comprehensive income 0 0  
Total 36 (9)  
Level 3 | Financial assets at fair value through the income statement      
Disclosure of detailed information about financial instruments [line items]      
Trading income 13 0  
Other income (23) 55  
Other comprehensive income 0 0  
Total (10) 55  
Level 3 | Fair value through other comprehensive income      
Disclosure of detailed information about financial instruments [line items]      
Trading income 4 3  
Other income (1) 22  
Other comprehensive income 0 0  
Total £ 3 £ 25