v3.26.1
Trade and other receivables - Schedule of receivables by geographical area (Details) - GBP (£)
£ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of financial assets [line items]      
Trade receivables £ 3,587 £ 6,429  
Accrued income 882 1,083  
Trade receivables and accrued income, net 3,370 3,555  
UK      
Disclosure of financial assets [line items]      
Trade receivables and accrued income, net 478 775  
US      
Disclosure of financial assets [line items]      
Trade receivables and accrued income, net 2,892 2,780  
Gross carrying amount      
Disclosure of financial assets [line items]      
Accrued income 882 1,083  
Gross carrying amount | UK      
Disclosure of financial assets [line items]      
Accrued income 289 513  
Gross carrying amount | US      
Disclosure of financial assets [line items]      
Accrued income 593 570  
Trade receivables | Gross carrying amount      
Disclosure of financial assets [line items]      
Trade receivables 3,091 3,050  
Trade receivables | Gross carrying amount | UK      
Disclosure of financial assets [line items]      
Trade receivables 194 265  
Trade receivables | Gross carrying amount | US      
Disclosure of financial assets [line items]      
Trade receivables 2,897 2,785  
Trade receivables | Accumulated impairment      
Disclosure of financial assets [line items]      
Trade receivables (603) (578) £ (559)
Trade receivables | Accumulated impairment | UK      
Disclosure of financial assets [line items]      
Trade receivables (5) (3)  
Trade receivables | Accumulated impairment | US      
Disclosure of financial assets [line items]      
Trade receivables £ (598) £ (575)