v3.26.1
Financial instruments - valuation - Level 3 Sensitivities of Liabilities (Details) - GBP (£)
£ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Fair value of liabilities        
Specified target level of certainty for assumptions of unobservable inputs 90.00%      
At fair value        
Fair value of liabilities        
Liabilities £ 111,913 £ 107,850    
At fair value | Trading deposits        
Fair value of liabilities        
Liabilities 40,399 41,284    
At fair value | Short positions, trading        
Fair value of liabilities        
Liabilities 10,023 7,504    
At fair value | Interest rate        
Fair value of liabilities        
Liabilities 25,465 26,758    
At fair value | Foreign exchange        
Fair value of liabilities        
Liabilities 30,663 27,042    
At fair value | Other derivatives        
Fair value of liabilities        
Liabilities 128 174    
At fair value | Debt securities in issue        
Fair value of liabilities        
Liabilities 2,341 2,305    
At fair value | Other deposits        
Fair value of liabilities        
Liabilities 2,449 2,312    
At fair value | Level 3        
Fair value of liabilities        
Liabilities 291 309 £ 398 £ 494
Sensitivity favourable 10 10    
Sensitivity unfavourable (10) (30)    
At fair value | Level 3 | Short positions, trading        
Fair value of liabilities        
Liabilities 1 1    
At fair value | Level 3 | Derivatives        
Fair value of liabilities        
Liabilities 261 278 £ 342 £ 465
At fair value | Level 3 | Interest rate        
Fair value of liabilities        
Liabilities 181 169    
Sensitivity favourable 10 10    
Sensitivity unfavourable (10) (10)    
At fair value | Level 3 | Foreign exchange        
Fair value of liabilities        
Liabilities 52 54    
At fair value | Level 3 | Other derivatives        
Fair value of liabilities        
Liabilities 28 55    
At fair value | Level 3 | Debt securities in issue        
Fair value of liabilities        
Liabilities 3 3    
At fair value | Level 3 | Other deposits        
Fair value of liabilities        
Liabilities £ 26 27    
Sensitivity unfavourable   £ (20)