v3.25.2
Cash flow - additional information (Details)
£ in Millions, $ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
GBP (£)
Jun. 30, 2025
USD ($)
Jun. 30, 2024
GBP (£)
Dec. 31, 2025
GBP (£)
Disclosure Of Cash Flow [Line Items]        
Decrease in net cash generated from operating activities £ 856      
Payments of litigation claim settlements 410   £ 298  
Income taxes paid, classified as operating activities 1,576   1,153  
Research and development expense 174   168  
Net cash used in investing activities 1,012   1,433  
Increase in net cash used in investing activities (421)      
Net proceeds from disposal of shares in associate, net of tax 1,052   1,577  
Purchase of short term investment products, including treasury bills (14)   107  
Purchase of property, plant and equipment, classified as investing activities 103   116  
Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets £ 140   146  
Increase in purchases of property plant and equipment and intangibles (4.40%) (4.40%)    
Net cash generated in financing activities £ 4,117   3,358  
Outflow due to dividend payment 2,609   2,605  
Interest paid, classified as financing activities 879   889  
Net inflow (outflow) from borrowings 505   868  
Outflows relating to derivative financial instruments 445   115  
Purchases of own shares 450   £ 366  
U.S.        
Disclosure Of Cash Flow [Line Items]        
Income taxes paid, classified as operating activities 209 $ 271    
Factoring of receivables        
Disclosure Of Cash Flow [Line Items]        
Amount factored 674      
Other payables £ 122      
Forecast        
Disclosure Of Cash Flow [Line Items]        
Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets       £ 650