v3.26.1
CONTINGENT LIABILITIES AND COMMITMENTS - Additional Information (Details)
€ in Millions, £ in Millions
6 Months Ended
Jun. 30, 2026
GBP (£)
Jun. 30, 2026
EUR (€)
Jun. 30, 2026
EUR (€)
Dec. 31, 2025
GBP (£)
Disclosure of contingent liabilities [line items]        
Provisions £ 950     £ 683
UK&I Banks        
Disclosure of contingent liabilities [line items]        
Preferred stock issued, threshold value 0      
Maximum        
Disclosure of contingent liabilities [line items]        
Santander UK liability under indemnity cap | €     € 40  
Maximum | UK&I MIFs        
Disclosure of contingent liabilities [line items]        
Estimated effect of litigation | €     € 1,000  
Minimum        
Disclosure of contingent liabilities [line items]        
Losses on litigation settlements | €   € 1,000    
Interest refund customer remediation        
Disclosure of contingent liabilities [line items]        
Provisions 623      
Interest refund customer remediation | Maximum        
Disclosure of contingent liabilities [line items]        
Provisions 684      
Litigation and other regulatory | AXA France        
Disclosure of contingent liabilities [line items]        
Litigation settlement, maximum potential exposure £ 528