v3.25.4
Related party transactions and Directors' remuneration - Narrative (Details) - GBP (£)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of transactions between related parties [line items]      
Accruing benefits under defined benefit scheme £ 348,000,000 £ 329,000,000 £ 298,000,000
Notional contract amount 100,079,291,000,000 83,792,768,000,000  
Defined contribution schemes      
Disclosure of transactions between related parties [line items]      
Accruing benefits under defined benefit scheme 172,000,000 178,000,000 180,000,000
Pension funds      
Disclosure of transactions between related parties [line items]      
Derivatives transacted 89,000,000 100,000,000  
Key management personnel and connected persons      
Disclosure of transactions between related parties [line items]      
Total commitments outstanding 100,000 100,000  
Amounts payable, related party transactions 14,800,000 9,500,000  
Director      
Disclosure of transactions between related parties [line items]      
Accruing benefits under defined benefit scheme 0    
Loans issued during the year 0 0  
Total value of guarantees entered into on behalf of Directors 0 0  
Director | Redundancy and restructuring      
Disclosure of transactions between related parties [line items]      
Amounts payable, related party transactions 15,300 7,398 30,519
Director | Defined contribution schemes      
Disclosure of transactions between related parties [line items]      
Defined benefit contributions paid 0 0 0
Notional contract amount 0 0 0
Highest paid director      
Disclosure of transactions between related parties [line items]      
Accruing benefits under defined benefit scheme 0 0 0
Commitments made by entity, related party transactions £ 0 £ 0 £ 0