Bonus Tax Calculator 2026/27
A bonus is taxed on top of your salary, so it's taxed at your highest rate. Enter your salary and bonus to see the income tax, National Insurance and what you keep.
Last updated 4 July 2026 · Written and reviewed by Mustafa Bilgic
Bonus tax calculator
Tax and NI on a one-off bonus, 2026/27.
England, Wales & NI estimate. Bonuses can be paid into a pension to save tax — see GOV.UK.
Why a bonus feels so heavily taxed
There is no separate "bonus tax" in the UK. Your bonus is simply added to your earnings for the year, which means it's taxed at your marginal rate — the rate on the top slice of your income. If your salary already uses up your personal allowance and pushes you towards the higher-rate band, the bonus can be taxed at 40% plus 2% National Insurance, so keeping little more than half of it is normal rather than a mistake.
A £5,000 bonus on a £40,000 salary is taxed at 20% (£1,000) plus 8% NI (£400), so you keep £3,600. The same bonus on a £55,000 salary is taxed at 40% plus 2% NI, so you keep only £2,900.
How the calculator works it out
We work out the income tax and National Insurance you'd pay on your salary alone, then again on your salary plus the bonus. The difference between the two is the tax and NI attributable to the bonus — an exact marginal calculation that automatically handles the awkward cases, such as a bonus that straddles two tax bands or one that tips you into the £100,000 personal-allowance taper. It's the same method behind our take-home pay calculator.
The £100,000 trap
A bonus that pushes your total income above £100,000 is punishing. Between £100,000 and £125,140 your personal allowance is withdrawn by £1 for every £2 earned, creating an effective 60% marginal rate. A £10,000 bonus in that zone can leave you with only £4,000 after tax and NI. This is exactly where paying the bonus straight into a pension pays off, because a pension contribution reduces your adjusted net income and can restore the lost allowance.
Sacrificing a bonus into a pension
Many employers let you divert some or all of a bonus into your pension before it's taxed — often called bonus sacrifice. Because the money never counts as taxable pay, you avoid income tax and National Insurance on the sacrificed amount, and some employers pass on their own NI saving too. For a higher-rate taxpayer, £1,000 of bonus sacrificed can add well over £1,000 to the pension for a take-home cost of around £580. Our pension tax relief calculator and salary sacrifice calculator show the trade-off.
Emergency tax on bonuses
Sometimes a bonus month triggers a larger-than-expected deduction because payroll temporarily applies a higher cumulative tax figure. This usually corrects itself over the following months as the annual calculation catches up, or through a refund at year end. If your bonus lands in a single pay packet, don't be alarmed if that month's tax looks steep — over the year it evens out to the marginal figure shown here. You can check the detail against your payslip and tax code on GOV.UK.
Frequently asked questions
How much tax will I pay on my bonus?
Your bonus is taxed at your marginal rate — the rate on the top of your income. A basic-rate taxpayer pays 20% tax and 8% NI, keeping 72%. A higher-rate taxpayer pays 40% tax and 2% NI, keeping 58%. Enter your salary and bonus above to see your exact figure.
Is there a special bonus tax rate in the UK?
No. A bonus is treated as ordinary earnings and added to your salary for the year, so it's taxed at whatever rate applies to that top slice of income. It can feel like a special rate because bonuses often fall entirely in the higher-rate band.
Can I avoid tax on my bonus?
You can't avoid it, but you can reduce it by paying some or all of the bonus into your pension before it's taxed — known as bonus sacrifice. This avoids both income tax and National Insurance on the sacrificed amount, which is very tax-efficient for higher earners.
Why was so much tax taken from my bonus this month?
Payroll works out tax cumulatively, so a large one-off bonus can trigger a temporarily high deduction. It usually corrects over the next few pay periods or at year end. Over the full year, the tax settles at the marginal rate shown here.
Does a bonus affect my student loan and pension?
Yes. A bonus increases the pay that student loan repayments and percentage-based pension contributions are calculated on for that period, so both deductions rise in the month the bonus is paid.