v3.25.4
Intangible Assets - Summary of Intangible Assets (Detail) - GBP (£)
£ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance £ 3,026 £ 3,091
Ending balance 3,009 3,026
Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 4,865 4,879
Exchange differences (225) (7)
Disposals and retirements (15) (95)
Acquisition through business combination 173 2
Transfers 0 (5)
Ending balance 4,903 4,865
Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 105 91
Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (1,839) (1,788)
Exchange differences 83 11
Charge for the year (153) (158)
Disposals and retirements 15 95
Transfers 0 1
Ending balance (1,894) (1,839)
Goodwill [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 2,437 2,434
Ending balance 2,425 2,437
Goodwill [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 2,437 2,434
Exchange differences (114) 2
Disposals and retirements 0 0
Acquisition through business combination 102 1
Transfers 0 0
Ending balance 2,425 2,437
Goodwill [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Goodwill [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Goodwill [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 0 0
Exchange differences 0 0
Charge for the year 0 0
Disposals and retirements 0 0
Transfers 0 0
Ending balance 0 0
Software [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 346 372
Ending balance 321 346
Software [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 1,146 1,137
Exchange differences (56) 12
Disposals and retirements (15) (89)
Acquisition through business combination 0 0
Transfers 0 (5)
Ending balance 1,180 1,146
Software [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 105 91
Software [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Software [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (800) (765)
Exchange differences 38 (8)
Charge for the year (112) (117)
Disposals and retirements 15 89
Transfers 0 1
Ending balance (859) (800)
Acquired customer lists, contracts and relationships [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 129 146
Ending balance 160 129
Acquired customer lists, contracts and relationships [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 586 580
Exchange differences (33) 6
Disposals and retirements 0 0
Acquisition through business combination 54 0
Transfers 0 0
Ending balance 607 586
Acquired customer lists, contracts and relationships [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired customer lists, contracts and relationships [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired customer lists, contracts and relationships [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (457) (434)
Exchange differences 26 (6)
Charge for the year (16) (17)
Disposals and retirements 0 0
Transfers 0 0
Ending balance (447) (457)
Acquired trademarks and brands [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 23 29
Ending balance 20 23
Acquired trademarks and brands [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 176 184
Exchange differences (6) (7)
Disposals and retirements 0 (1)
Acquisition through business combination 3 0
Transfers 0 0
Ending balance 173 176
Acquired trademarks and brands [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired trademarks and brands [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired trademarks and brands [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (153) (155)
Exchange differences 5 7
Charge for the year (5) (6)
Disposals and retirements 0 1
Transfers 0 0
Ending balance (153) (153)
Acquired publishing rights [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 1 1
Ending balance 1 1
Acquired publishing rights [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 100 100
Exchange differences (3) 0
Disposals and retirements 0 0
Acquisition through business combination 0 0
Transfers 0 0
Ending balance 97 100
Acquired publishing rights [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired publishing rights [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Acquired publishing rights [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (99) (99)
Exchange differences 3 0
Charge for the year 0 0
Disposals and retirements 0 0
Transfers 0 0
Ending balance (96) (99)
Other intangibles acquired [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 90 109
Ending balance 82 90
Other intangibles acquired [member] | Cost [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 420 444
Exchange differences (13) (20)
Disposals and retirements 0 (5)
Acquisition through business combination 14 1
Transfers 0 0
Ending balance 421 420
Other intangibles acquired [member] | Cost [member] | Internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Other intangibles acquired [member] | Cost [member] | Not internally generated [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Additions 0 0
Other intangibles acquired [member] | Depreciation [member]    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance (330) (335)
Exchange differences 11 18
Charge for the year (20) (18)
Disposals and retirements 0 5
Transfers 0 0
Ending balance £ (339) £ (330)