v3.25.4
Income Tax - Summary of Profit Before Tax Differences Calculated (Detail) - GBP (£)
£ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Reconciliation of Effective Tax Rate [Line Items]      
Profit before tax £ 457 £ 510 £ 493
Tax calculated at UK rate (2025: 25%; 2024: 25%; 2023: 23.5%) (114) (127) (116)
Effect of overseas tax rates (3) (1) (1)
Effect of UK rate change 0 0 (1)
Net (expense)/income not subject to tax (5) 3 (3)
Gains and losses on sale of businesses not subject to tax 0 0 5
Unrecognised tax losses 6 2 1
State Aid Provision Release 0 63 0
Movement in provisions for tax uncertainties – current year (1) (1) (2)
Movement in provisions for tax uncertainties – prior years (4) (12) 1
Other prior year adjustments 0 (2) 3
Total tax charge £ (121) £ (75) £ (113)
Tax rate reflected in earnings 26.50% 14.70% 23.00%
UK [member]      
Reconciliation of Effective Tax Rate [Line Items]      
Total tax charge £ (41) £ 21 £ (54)
Overseas [member]      
Reconciliation of Effective Tax Rate [Line Items]      
Total tax charge £ (80) £ (96) £ (59)