Commitments and contingencies (Details) £ in Millions |
Sep. 30, 2025
GBP (£)
|
Mar. 31, 2025
GBP (£)
|
|---|---|---|
| Disclosure of contingent liabilities [line items] | ||
| Energy purchase commitments | £ 13,649 | £ 13,880 |
| Contractual capital commitments | £ 6,520 | £ 4,949 |
| Maximum | ||
| Disclosure of contingent liabilities [line items] | ||
| License breach penalty, percentage of turnover | 0.10 |