CONTINGENT LIABILITIES AND COMMITMENTS - Summary of Contingent Liabilities and Commitments (Details) - GBP (£) £ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Disclosure Of Contingent Liabilities And Commitments [Line Items] | ||
| Guarantees and formal standby facilities, credit lines and other commitments | £ 41,797 | £ 38,821 |
| Guarantees given to third parties | ||
| Disclosure Of Contingent Liabilities And Commitments [Line Items] | ||
| Guarantees given to third parties | 940 | 716 |
| Formal standby facilities, credit lines and other commitments | ||
| Disclosure Of Contingent Liabilities And Commitments [Line Items] | ||
| Formal standby facilities, credit lines and other commitments | £ 40,857 | £ 38,105 |