Contingent liabilities and commitments (Details) - GBP (£) £ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Total commitments and contingent liabilities | ||
| Disclosure of contingent liabilities [line items] | ||
| Notional amount | £ 456,462 | £ 449,980 |
| Guarantees and letters of credit pledged as collateral security | ||
| Disclosure of contingent liabilities [line items] | ||
| Notional amount | 17,687 | 16,749 |
| Performance guarantees, acceptances and endorsements | ||
| Disclosure of contingent liabilities [line items] | ||
| Notional amount | 8,235 | 8,625 |
| Documentary credits and other short-term trade related transactions | ||
| Disclosure of contingent liabilities [line items] | ||
| Notional amount | 1,263 | 1,103 |
| Standby facilities, credit lines and other commitments | ||
| Disclosure of contingent liabilities [line items] | ||
| Notional amount | £ 429,277 | £ 423,503 |