v3.26.1
OTHER FINANCIAL ASSETS AT FAIR VALUE THROUGH PROFIT OR LOSS (Details) - GBP (£)
£ in Millions
Jun. 30, 2026
Dec. 31, 2025
Disclosure Of Other Financial Assets At Fair Value Through Profit Or Loss [Line Items]    
Financial assets at fair value through profit or loss £ 53 £ 64
Loans and advances to customers:    
Disclosure Of Other Financial Assets At Fair Value Through Profit Or Loss [Line Items]    
Financial assets at fair value through profit or loss 31 40
Other debt instruments    
Disclosure Of Other Financial Assets At Fair Value Through Profit Or Loss [Line Items]    
Financial assets at fair value through profit or loss £ 22 £ 24