v3.26.1
Fair value of financial instruments - Unrealised gains and losses recognised in the period on Level 3 assets and liabilities held at period end (Details) - GBP (£)
£ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Disclosure of detailed information about financial instruments [line items]    
Trading income £ 4,623 £ 4,171
Other income [1] 257 37
Other comprehensive income (252) 873
Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income 174 233
Other income 19 38
Other comprehensive income 0 0
Total 193 271
Significant unobservable inputs (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
Significant unobservable inputs (Level 3) | Derivatives    
Disclosure of detailed information about financial instruments [line items]    
Trading income 104 164
Other income 1 3
Other comprehensive income 0 0
Total 105 167
Trading portfolio liabilities | Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income 12 34
Other income 0 0
Other comprehensive income 0 0
Total 12 34
Financial liabilities designated at fair value | Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income 70 87
Other income 0 0
Other comprehensive income 0 0
Total 70 87
Trading portfolio assets | Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income 26 21
Other income 0 0
Other comprehensive income 0 0
Total 26 21
Financial assets at fair value through the income statement | Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income (46) (74)
Other income 18 7
Other comprehensive income 0 0
Total (28) (67)
Financial assets at fair value through other comprehensive income | Significant unobservable inputs (Level 3)    
Disclosure of detailed information about financial instruments [line items]    
Trading income 8 1
Other income 0 28
Other comprehensive income 0 0
Total £ 8 £ 29
[1] Other income includes c.£225m gain recognised on sale of the AA portfolio on 24 April 2026.