Taxation (Details) - GBP (£) £ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Major components of tax expense (income) [abstract] | ||
| Average effective tax rate | 18.10% | 18.60% |
| Adjusting items included in taxation | £ 66 | £ 36 |
| Tax on adjusting items | £ 29 | £ 151 |
| Average effective tax rate for subsidiaries | 24.40% | 24.40% |