v3.26.1
Allowance for expected credit losses - Disclosure of Generation of Multiple Economic Assumptions by Quarter and by Year (Details)
Jun. 30, 2026
Dec. 31, 2025
2026 to 2030 average % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.80% 1.80%
Unemployment rate 3.60% 3.70%
House price growth 5.50% 4.80%
Commercial real estate price growth 3.10% 3.20%
UK Bank Rate 4.99% 4.61%
CPI inflation 2.70% 2.90%
2026 to 2030 average % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.40% 1.40%
Unemployment rate 5.00% 4.80%
House price growth 2.20% 1.90%
Commercial real estate price growth 0.30% 0.90%
UK Bank Rate 3.58% 3.55%
CPI inflation 2.20% 2.60%
2026 to 2030 average % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.60% 0.70%
Unemployment rate 7.00% 6.70%
House price growth (2.50%) (2.60%)
Commercial real estate price growth (4.00%) (3.10%)
UK Bank Rate 1.59% 1.85%
CPI inflation 1.60% 2.10%
2026 to 2030 average % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth (0.10%) 0.00%
Unemployment rate 9.20% 8.50%
House price growth (6.80%) (6.50%)
Commercial real estate price growth (9.60%) (8.00%)
UK Bank Rate 0.85% 1.24%
CPI inflation 0.90% 1.60%
2026 to 2030 average % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.10% 1.20%
Unemployment rate 5.60% 5.40%
House price growth 0.90% 0.60%
Commercial real estate price growth (1.10%) (0.40%)
UK Bank Rate 3.13% 3.13%
CPI inflation 2.00% 2.40%
2026 % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.40% 1.40%
Unemployment rate 4.80% 4.80%
House price growth 1.80% 0.80%
Commercial real estate price growth 3.30% 1.20%
UK Bank Rate 3.85% 4.13%
CPI inflation 3.10% 3.40%
2026 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.00% 1.40%
Unemployment rate 5.20% 4.80%
House price growth 0.90% 0.80%
Commercial real estate price growth (0.30%) 1.20%
UK Bank Rate 3.75% 4.13%
CPI inflation 3.10% 3.40%
2026 % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.60% 1.40%
Unemployment rate 5.60% 4.80%
House price growth 0.00% 0.80%
Commercial real estate price growth (3.50%) 1.20%
UK Bank Rate 3.65% 4.13%
CPI inflation 3.10% 3.40%
2026 % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.10% 1.40%
Unemployment rate 6.20% 4.80%
House price growth (1.00%) 0.80%
Commercial real estate price growth (8.60%) 1.20%
UK Bank Rate 3.49% 4.13%
CPI inflation 3.10% 3.40%
2026 % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.90% 1.40%
Unemployment rate 5.30% 4.80%
House price growth 0.70% 0.80%
Commercial real estate price growth (1.00%) 1.20%
UK Bank Rate 3.72% 4.13%
CPI inflation 3.10% 3.40%
First quarter 2026 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.60% 0.70%
Unemployment rate 5.00% 4.50%
House price growth 0.80% 2.90%
Commercial real estate price growth 0.80% 2.50%
UK Bank Rate 3.75% 4.50%
CPI inflation 3.10% 2.80%
Second quarter 2026 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.10% 0.30%
Unemployment rate 5.00% 4.70%
House price growth 0.50% 2.70%
Commercial real estate price growth 0.30% 2.60%
UK Bank Rate 3.75% 4.25%
CPI inflation 2.80% 3.50%
Third quarter 2026 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.10% 0.10%
Unemployment rate 5.20% 5.00%
House price growth 0.30% 1.30%
Commercial real estate price growth (0.20%) 2.60%
UK Bank Rate 3.75% 4.00%
CPI inflation 3.00% 3.80%
Fourth quarter 2026 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.20% 0.30%
Unemployment rate 5.40% 5.10%
House price growth 0.90% 0.80%
Commercial real estate price growth (0.30%) 1.20%
UK Bank Rate 3.75% 3.75%
CPI inflation 3.30% 3.70%
2027 % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 2.40% 2.00%
Unemployment rate 3.70% 4.20%
House price growth 4.50% 3.50%
Commercial real estate price growth 6.60% 7.90%
UK Bank Rate 4.79% 3.94%
CPI inflation 2.50% 2.60%
2027 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.00% 1.20%
Unemployment rate 5.40% 5.20%
House price growth 1.20% 1.60%
Commercial real estate price growth 0.00% 0.60%
UK Bank Rate 3.63% 3.44%
CPI inflation 2.40% 2.60%
2027 % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth (1.20%) (0.30%)
Unemployment rate 7.50% 6.60%
House price growth (2.40%) (0.20%)
Commercial real estate price growth (8.70%) (7.10%)
UK Bank Rate 2.04% 2.74%
CPI inflation 2.30% 2.60%
2027 % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth (3.30%) (1.90%)
Unemployment rate 10.10% 8.30%
House price growth (5.10%) (1.20%)
Commercial real estate price growth (17.80%) (17.40%)
UK Bank Rate 0.64% 1.91%
CPI inflation 2.20% 2.60%
2027 % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.40% 0.70%
Unemployment rate 6.00% 5.60%
House price growth 0.50% 1.30%
Commercial real estate price growth (2.40%) (1.30%)
UK Bank Rate 3.20% 3.23%
CPI inflation 2.30% 2.60%
First quarter 2027 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.30% 0.30%
Unemployment rate 5.50% 5.30%
House price growth 0.60% 1.30%
Commercial real estate price growth (0.30%) 0.50%
UK Bank Rate 3.75% 3.75%
CPI inflation 2.90% 3.30%
Second quarter 2027 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.30% 0.30%
Unemployment rate 5.40% 5.30%
House price growth 1.20% 1.60%
Commercial real estate price growth (0.20%) 0.20%
UK Bank Rate 3.75% 3.50%
CPI inflation 2.50% 2.60%
Third quarter 2027 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.30% 0.40%
Unemployment rate 5.30% 5.20%
House price growth 1.40% 1.60%
Commercial real estate price growth (0.10%) 0.10%
UK Bank Rate 3.50% 3.25%
CPI inflation 2.00% 2.20%
Fourth quarter 2027 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.30% 0.40%
Unemployment rate 5.20% 5.10%
House price growth 1.20% 1.60%
Commercial real estate price growth 0.00% 0.60%
UK Bank Rate 3.50% 3.25%
CPI inflation 1.90% 2.20%
2028 % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.90% 2.30%
Unemployment rate 3.10% 3.20%
House price growth 7.70% 7.10%
Commercial real estate price growth 3.10% 4.90%
UK Bank Rate 5.19% 4.59%
CPI inflation 2.20% 2.40%
2028 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.50% 1.40%
Unemployment rate 5.00% 4.80%
House price growth 2.00% 1.90%
Commercial real estate price growth 0.90% 1.70%
UK Bank Rate 3.50% 3.25%
CPI inflation 1.80% 2.20%
2028 % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 0.50% (0.50%)
Unemployment rate 7.70% 7.50%
House price growth (5.40%) (4.70%)
Commercial real estate price growth (3.20%) (4.20%)
UK Bank Rate 1.04% 1.09%
CPI inflation 1.20% 2.00%
2028 % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth (0.10%) (1.80%)
Unemployment rate 10.40% 10.20%
House price growth (12.40%) (11.10%)
Commercial real estate price growth (8.70%) (9.80%)
UK Bank Rate 0.07% 0.10%
CPI inflation 0.60% 1.70%
2028 % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.10% 0.80%
Unemployment rate 5.80% 5.70%
House price growth 0.00% 0.20%
Commercial real estate price growth (0.60%) (0.30%)
UK Bank Rate 2.93% 2.69%
CPI inflation 1.60% 2.20%
2029 % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.60% 1.60%
Unemployment rate 3.10% 3.10%
House price growth 7.50% 6.90%
Commercial real estate price growth 2.00% 1.70%
UK Bank Rate 5.46% 5.07%
CPI inflation 2.70% 2.80%
2029 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.60% 1.50%
Unemployment rate 4.70% 4.60%
House price growth 3.40% 2.20%
Commercial real estate price growth 0.80% 0.50%
UK Bank Rate 3.50% 3.44%
CPI inflation 1.80% 2.20%
2029 % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.40% 1.10%
Unemployment rate 7.30% 7.40%
House price growth (3.20%) (5.70%)
Commercial real estate price growth (2.10%) (2.70%)
UK Bank Rate 0.71% 0.75%
CPI inflation 0.70% 1.40%
2029 % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.20% 0.70%
Unemployment rate 9.80% 9.90%
House price growth (9.20%) (12.20%)
Commercial real estate price growth (6.50%) (7.40%)
UK Bank Rate 0.02% 0.03%
CPI inflation (0.50%) 0.50%
2029 % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.50% 1.30%
Unemployment rate 5.50% 5.50%
House price growth 1.40% (0.20%)
Commercial real estate price growth (0.40%) (0.90%)
UK Bank Rate 2.90% 2.78%
CPI inflation 1.50% 2.00%
2030 % | Upside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.60% 1.60%
Unemployment rate 3.30% 3.20%
House price growth 6.00% 6.00%
Commercial real estate price growth 0.70% 0.80%
UK Bank Rate 5.65% 5.33%
CPI inflation 3.00% 3.10%
2030 % | Base case    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.60% 1.60%
Unemployment rate 4.70% 4.50%
House price growth 3.40% 3.10%
Commercial real estate price growth 0.00% 0.20%
UK Bank Rate 3.50% 3.50%
CPI inflation 2.00% 2.30%
2030 % | Downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.70% 1.60%
Unemployment rate 7.00% 7.00%
House price growth (1.30%) (2.80%)
Commercial real estate price growth (2.70%) (2.30%)
UK Bank Rate 0.49% 0.52%
CPI inflation 0.60% 1.00%
2030 % | Severe downside    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.50% 1.40%
Unemployment rate 9.30% 9.40%
House price growth (6.00%) (7.80%)
Commercial real estate price growth (6.10%) (5.40%)
UK Bank Rate 0.01% 0.01%
CPI inflation (1.00%) (0.40%)
2030 % | Probability-weighted    
Allowance For Impairment Losses [Line Items]    
Gross domestic product growth 1.60% 1.60%
Unemployment rate 5.40% 5.40%
House price growth 1.80% 1.10%
Commercial real estate price growth (1.20%) (0.90%)
UK Bank Rate 2.89% 2.81%
CPI inflation 1.60% 1.90%