Bonus tax calculator
There is no separate bonus tax rate in the UK. A bonus is ordinary pay stacked on top of your salary, so it is taxed at your marginal rate, 28% for a basic-rate taxpayer once NI is counted, 42% at higher rate, and over 60% inside the £100k taper.
Of your £5,000 bonus, you keep
£3,600.00
£1,400.00 (28%) goes in tax and National Insurance, the bonus is taxed at your marginal rate, on top of everything you already earn.
“My bonus was taxed at 50%!”, the payroll month illusion
PAYE spreads your allowance and bands evenly across the year. A bonus lands in one month, so that month's pay is taxed as if you earned it every month, which over-deducts in the bonus month and quietly corrects itself over the rest of the year. The annual figures above are the true position; the payslip shock is timing, not extra tax.
Ways to keep more of a bonus
- Bonus sacrifice: paid into your pension before tax and NI, so £100 of bonus becomes £100 of pension instead of £58-72 of cash. Most valuable inside the taper. See the salary sacrifice calculator.
- Timing: if a bonus would tip you over £100,000 of adjusted net income and you have young children, the childcare loss can exceed the bonus itself; a pension contribution restores it.
- Student loans: repayments are per pay period, so a bonus month triggers 9% on the excess even if your annual pay is near the threshold.
2026/27 rates, checked 2026-08-28. Annualised comparison, your bonus-month payslip will differ for the timing reason explained above. Method on the about page.