v3.26.1
Net fee and commission income (Details) - GBP (£)
£ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers £ 5,163 £ 4,883
Other non-contract fee income 101 79
Fee and commission income 5,264 4,962
Fee and commission expense (1,758) (1,742)
Net fee and commission income 3,506 3,220
Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,720 1,878
Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 626 448
Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,177 1,058
Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,571 1,442
Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 69 57
Operating segments | Barclays UK Corporate Bank    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 292 286
Other non-contract fee income 14 14
Fee and commission income 306 300
Fee and commission expense (46) (49)
Net fee and commission income 260 251
Operating segments | Barclays UK Corporate Bank | Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 229 229
Operating segments | Barclays UK Corporate Bank | Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Operating segments | Barclays UK Corporate Bank | Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Operating segments | Barclays UK Corporate Bank | Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 58 51
Operating segments | Barclays UK Corporate Bank | Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 5 6
Operating segments | Barclays Private Bank and Wealth Management    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 280 262
Other non-contract fee income 0 0
Fee and commission income 280 262
Fee and commission expense (21) (19)
Net fee and commission income 259 243
Operating segments | Barclays Private Bank and Wealth Management | Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 14 15
Operating segments | Barclays Private Bank and Wealth Management | Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 174 166
Operating segments | Barclays Private Bank and Wealth Management | Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 91 79
Operating segments | Barclays Private Bank and Wealth Management | Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Operating segments | Barclays Private Bank and Wealth Management | Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1 2
Operating segments | Barclays Investment Bank    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 3,203 2,857
Other non-contract fee income 87 65
Fee and commission income 3,290 2,922
Fee and commission expense (738) (677)
Net fee and commission income 2,552 2,245
Operating segments | Barclays Investment Bank | Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 165 171
Operating segments | Barclays Investment Bank | Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 452 282
Operating segments | Barclays Investment Bank | Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,086 979
Operating segments | Barclays Investment Bank | Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,451 1,391
Operating segments | Barclays Investment Bank | Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 49 34
Operating segments | Barclays US Consumer Bank    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,267 1,333
Other non-contract fee income 0 0
Fee and commission income 1,267 1,333
Fee and commission expense (921) (959)
Net fee and commission income 346 374
Operating segments | Barclays US Consumer Bank | Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 1,205 1,333
Operating segments | Barclays US Consumer Bank | Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Operating segments | Barclays US Consumer Bank | Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Operating segments | Barclays US Consumer Bank | Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 62 0
Operating segments | Barclays US Consumer Bank | Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Head Office    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 121 145
Other non-contract fee income 0 0
Fee and commission income 121 145
Fee and commission expense (32) (38)
Net fee and commission income 89 107
Head Office | Transactional    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 107 130
Head Office | Advisory    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Head Office | Brokerage and execution    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Head Office | Underwriting and syndication    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers 0 0
Head Office | Other    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Total revenue from contracts with customers £ 14 £ 15