v3.26.1
Adjusting items - Narrative (Details)
£ in Millions, $ in Millions
 1 Months Ended 6 Months Ended 12 Months Ended 30 Months Ended
Dec. 31, 2028
GBP (£)
Jun. 30, 2026
GBP (£)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
GBP (£)
Jun. 30, 2026
GBP (£)
Dec. 31, 2025
GBP (£)
Dec. 31, 2027
GBP (£)
Disclosure of attribution of expenses by nature to their function [line items]              
Adjusting items included in profit from operations   £ (4,266)   £ (5,069)      
Expense of restructuring activities   228     £ 482    
Restructuring   370   13      
Impairment loss recognised in profit or loss, goodwill   0   72      
Other adjusting items which have been adjusted within other operating expenses   32   8      
Gains (losses) on litigation settlements   171   30      
Credit in respect of the Canada Approved Plans   £ (38)   £ (575)      
Actuarial assumption of discount rates   3.86%   3.79% 3.86%    
ITG Brands              
Disclosure of attribution of expenses by nature to their function [line items]              
Credit in respect of settlement of historical litigations with ITG brands   £ 149 $ 200 £ 0      
Peru              
Disclosure of attribution of expenses by nature to their function [line items]              
Impairment loss recognised in profit or loss, goodwill   0   72      
Romania              
Disclosure of attribution of expenses by nature to their function [line items]              
Credit in respect of Romania's other taxes   £ (2)   (22)      
Canada              
Disclosure of attribution of expenses by nature to their function [line items]              
Percentage of net income after taxes used for adjustment   85.00% 85.00%     100.00%  
Other adjusting items which have been adjusted within other operating expenses   £ 575          
Payment period   40 years 40 years        
Other non-current provisions   £ 2,752     £ 2,752 £ 2,794  
Canada | Six months              
Disclosure of attribution of expenses by nature to their function [line items]              
Trade and other payables   83     £ 83    
Trademarks and similar intangibles              
Disclosure of attribution of expenses by nature to their function [line items]              
Amortisation and impairment of trademarks and similar intangibles   £ 796   804      
Trademarks and similar intangibles | Top of range              
Disclosure of attribution of expenses by nature to their function [line items]              
Intangibles assets expected useful lives   30 years 30 years        
Adj items              
Disclosure of attribution of expenses by nature to their function [line items]              
Adjusting items included in profit from operations   £ (1,160)   £ (325)      
Restructuring             £ 459
Forecast              
Disclosure of attribution of expenses by nature to their function [line items]              
Business combination restructuring and integration costs, cash items             620
Anticipated Cost Savings From Restructuring Plan £ 100            
Restructuring             950
Business combination restructuring and integration costs, non-cash items             330
Forecast | Adj items              
Disclosure of attribution of expenses by nature to their function [line items]              
Restructuring             £ 840