v3.25.4
Financial instruments - Summary of movements in the hedge reserve including gains and losses on cash flow hedging instruments (Details) - GBP (£)
£ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about financial instruments      
(Losses)/gains arising during the period £ 55 £ 11 £ 29
Amounts recognised in income statement (36) (20) 18
Hedge reserve      
Disclosure of detailed information about financial instruments      
Hedge reserve balance at the start of the period: (losses)/gains deferred 27 36  
(Losses)/gains arising during the period 55 11  
Amounts recognised in income statement (36) (20)  
Hedge reserve balance at the end of the period: gains/(losses) deferred 46 27 36
Reserve of cash flow hedges, tax (11) (6)  
Interest rate hedge reserve      
Disclosure of detailed information about financial instruments      
Hedge reserve balance at the start of the period: (losses)/gains deferred (3)    
(Losses)/gains arising during the period 2 (5)  
Amounts recognised in income statement 1 2  
Hedge reserve balance at the end of the period: gains/(losses) deferred   (3)  
Cost of hedging reserve      
Disclosure of detailed information about financial instruments      
Hedge reserve balance at the start of the period: (losses)/gains deferred 2 (4)  
(Losses)/gains arising during the period (2) 6  
Hedge reserve balance at the end of the period: gains/(losses) deferred   2 (4)
Foreign currency hedge reserve      
Disclosure of detailed information about financial instruments      
Hedge reserve balance at the start of the period: (losses)/gains deferred 28 40  
(Losses)/gains arising during the period 55 10  
Amounts recognised in income statement (37) (22)  
Hedge reserve balance at the end of the period: gains/(losses) deferred £ 46 £ 28 £ 40