CREDIT IMPAIRMENT CHARGES - Summary of Impairment Losses and Provisions (Details) - GBP (£) £ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Disclosure Of Credit Impairment Loss And Provisions [Abstract] | ||
| Loans and advances to customers | £ 268 | £ 102 |
| Recoveries of loans and advances, net of collection costs | 6 | 10 |
| Off-balance sheet credit exposures (See Note 21) | 3 | (7) |
| Credit impairment charges/(write-backs): | £ 277 | £ 105 |