Credit risk - Schedule of Derivative Assets (Details) - GBP (£) £ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| FINANCIAL RISK MANAGEMENT (Details) - Schedule of Derivative Assets [Line Items] | ||
| Trading and other | £ 19,702 | £ 24,017 |
| Hedging | 25 | 48 |
| Total derivative financial instruments | 19,727 | 24,065 |
| Investment grade | ||
| FINANCIAL RISK MANAGEMENT (Details) - Schedule of Derivative Assets [Line Items] | ||
| Trading and other | 18,361 | 22,684 |
| Hedging | 24 | 39 |
| Total derivative financial instruments | 18,385 | 22,723 |
| Other | ||
| FINANCIAL RISK MANAGEMENT (Details) - Schedule of Derivative Assets [Line Items] | ||
| Trading and other | 1,341 | 1,333 |
| Hedging | 1 | 9 |
| Total derivative financial instruments | £ 1,342 | £ 1,342 |