v3.26.1
Revenue disaggregation and segmental analysis (Details) - EUR (€)
€ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue € 33,480 € 30,758 € 29,912
Equipment revenue 4,807 4,577 4,595
Revenue from contracts with customers 38,287 35,335 34,507
Other revenue 1,952 1,983 2,109
Interest revenue 222 130 101
Total segment revenue 40,461 37,448 36,717
Adjusted EBITDAaL 11,351 10,932 11,019
Amount of total future revenue from the Group's contracts with customers with performance obligations not satisfied 17,622 17,297 16,577
Not later than one year [Member]      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Amount of total future revenue from the Group's contracts with customers with performance obligations not satisfied 11,469 10,812 10,488
Common Functions      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 763 663 559
Equipment revenue 41 57 49
Revenue from contracts with customers 804 720 608
Other revenue 1,020 1,097 1,256
Interest revenue 1    
Total segment revenue 1,825 1,817 1,864
Adjusted EBITDAaL (164) 45 29
Eliminations      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue (121) (129) (150)
Equipment revenue     (1)
Revenue from contracts with customers (121) (129) (151)
Other revenue (78) (60) (76)
Total segment revenue (199) (189) (227)
Germany      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 10,874 10,876 11,453
Equipment revenue 890 942 1,132
Revenue from contracts with customers 11,764 11,818 12,585
Other revenue 346 345 357
Interest revenue 23 17 15
Total segment revenue 12,133 12,180 12,957
Adjusted EBITDAaL 4,243 4,384 5,017
UK      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 7,597 5,887 5,631
Equipment revenue 1,486 1,109 1,111
Revenue from contracts with customers 9,083 6,996 6,742
Other revenue 43 14 54
Interest revenue 66 59 41
Total segment revenue 9,192 7,069 6,837
Adjusted EBITDAaL 1,881 1,558 1,408
Other Europe      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 4,888 4,805 4,722
Equipment revenue 707 761 665
Revenue from contracts with customers 5,595 5,566 5,387
Other revenue 91 108 102
Interest revenue 28 20 15
Total segment revenue 5,714 5,694 5,504
Adjusted EBITDAaL 1,574 1,510 1,516
Turkey      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 2,826 2,484 1,746
Equipment revenue 526 595 609
Revenue from contracts with customers 3,352 3,079 2,355
Other revenue 8 7 7
Interest revenue 71    
Total segment revenue 3,431 3,086 2,362
Adjusted EBITDAaL 983 842 510
Africa      
Disclosure of disaggregation of revenue from contracts with customers [line items]      
Service revenue 6,653 6,172 5,951
Equipment revenue 1,157 1,113 1,030
Revenue from contracts with customers 7,810 7,285 6,981
Other revenue 522 472 409
Interest revenue 33 34 30
Total segment revenue 8,365 7,791 7,420
Adjusted EBITDAaL € 2,834 € 2,593 € 2,539