Borrowing facilities - Narrative (Details) - GBP (£) £ in Millions |
Mar. 31, 2024 |
Mar. 31, 2023 |
|---|---|---|
| Disclosure of detailed information about borrowings [line items] | ||
| Undrawn borrowing facilities | £ 7,905 | £ 6,503 |
| Facilities held as backup to commercial paper and similar borrowings | ||
| Disclosure of detailed information about borrowings [line items] | ||
| Undrawn borrowing facilities | 7,864 | 6,461 |
| Facilities available as backup to specific US borrowings | ||
| Disclosure of detailed information about borrowings [line items] | ||
| Undrawn borrowing facilities | £ 41 | £ 42 |