Costs of services and general and administrative costs - Narrative (Details) - GBP (£) £ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Disclosure Of Information About Operating Cost [line items] | ||
| Goodwill impairment | £ 0 | £ 116 |
| Restructuring and transformation costs | 83 | 40 |
| Elevate 24 | ||
| Disclosure Of Information About Operating Cost [line items] | ||
| Restructuring and transformation costs | 59 | |
| Historical restructuring programs | ||
| Disclosure Of Information About Operating Cost [line items] | ||
| Restructuring and transformation costs | £ 24 | £ 40 |