Related party transactions - Schedule of Loan Balances Outstanding (Details) - Key management personnel of entity or parent - GBP (£) £ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Loans | |||
| At 1 January | £ 1 | £ 1 | £ 2 |
| Advanced (includes loans to appointed key management personnel) | 1 | 1 | 0 |
| Repayments (includes loans to former key management personnel) | (1) | (1) | (1) |
| At 31 December | £ 1 | £ 1 | £ 1 |