v3.25.2
Legal, competition and regulatory matters (Details)
£ in Millions, $ in Millions
 1 Months Ended 6 Months Ended 12 Months Ended
Oct. 31, 2024
request
Jan. 31, 2024
decision
Nov. 30, 2023
request
Jan. 31, 2023
lawsuit
Apr. 30, 2021
USD ($)
Jun. 30, 2025
lawsuit
plaintiff
Dec. 31, 2018
GBP (£)
Dec. 31, 2008
USD ($)
Civil actions in respect of USD LIBOR                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           1    
Civil actions in respect of VRDO - SNDY                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           3    
Interest rate swap and credit default swap US civil actions                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           1    
Civil actions in respect of the US anti-terrorism act                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           8    
Number of plaintiffs | plaintiff           4,000    
Civil actions in respect of the US anti-terrorism act - EDNY                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought       6        
Number of lawsuits dismissed       3        
Number of lawsuits subject to appeal           1    
Number of lawsuits consolidated into a separate lawsuit           2    
Number of separate lawsuits           1    
Number of initial lawsuits amended           1    
Number of lawsuits stayed           2    
Civil actions in respect of the US anti-terrorism act - SDNY                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           2    
Motor finance commission arrangements                
Disclosure of contingent liabilities [line items]                
Number of final decisions by the UK Financial Ombudsman Service | decision   2            
Number of final decisions by the UK Financial Ombudsman Service about commision arrangements | decision   1            
Number of judgment issued in motor finance commission cases | request 3              
HMRC assessments concerning UK VAT                
Disclosure of contingent liabilities [line items]                
Loss contingency, damages sought, claimed amounts, value | £             £ 181  
HMRC assessments concerning UK VAT | Barclays UK PLC                
Disclosure of contingent liabilities [line items]                
Loss contingency, damages sought, claimed amounts, value | £             128  
Originated and sold to third parties by Acquired Subsidiary | RMBS repurchase requests | US residential and commercial mortgage-related activity and litigation                
Disclosure of contingent liabilities [line items]                
Number of lawsuits with damages sought           1    
Barclays Bank PLC | Other proceedings                
Disclosure of contingent liabilities [line items]                
Number of arbitration requests received | request     2          
Barclays Bank PLC | BDC Finance LLC                
Disclosure of contingent liabilities [line items]                
Litigation settlements approved, value | $         $ 3.3     $ 298.0
Barclays Bank PLC | HMRC assessments concerning UK VAT                
Disclosure of contingent liabilities [line items]                
Loss contingency, damages sought, claimed amounts, value | £             £ 53