DEPOSITS BY BANKS (Details) - GBP (£) £ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Disclosure Of Deposits From Banks [Line Items] | ||
| Deposits by banks | £ 7,865 | £ 6,628 |
| Deposits from banks, settlement activities | 500 | 503 |
| Drawdown from TFSME | 4,500 | 3,900 |
| Items in the course of transmission | ||
| Disclosure Of Deposits From Banks [Line Items] | ||
| Deposits by banks | 625 | 572 |
| Deposits held as collateral | ||
| Disclosure Of Deposits From Banks [Line Items] | ||
| Deposits by banks | 309 | 442 |
| Other deposits | ||
| Disclosure Of Deposits From Banks [Line Items] | ||
| Deposits by banks | 6,929 | 5,613 |
| Amounts due to other Santander UK Group Holdings plc subsidiaries | ||
| Disclosure Of Deposits From Banks [Line Items] | ||
| Deposits by banks | £ 2 | £ 1 |