Bonus Tax Calculator

Tax on a bonus is worked out like tax on salary: the bonus is added to your pay and taxed at your rate in the payslip it is paid with. A bonus is taxed exactly like the rest of your pay. It is added to your earnings, and you pay income tax and National Insurance on it at the rates for the tax year it is paid in. There is no special bonus rate. The only thing that is different is when the tax is taken: on the payslip the bonus arrives with.

On a salary of £39,000 a year, a £3,000 bonus paid in December leaves about £2,284: £600 income tax (20%) and £116 National Insurance. Change any figure in the calculator above to see your own.

The share you keep goes down as your salary goes up, because more of the bonus falls in a higher tax band. This table is for a £5,000 bonus paid in December on the standard tax code, with no student loan or pension.

The last row is different. At £98,000 the bonus takes income past £100,000, so part of it also costs personal allowance: you keep 46% of it. The section on bonuses over £100,000 below explains why.

Payroll does not tax each payday on its own. It adds up your pay so far this tax year and compares it with the allowance and the tax bands for the months so far. This is HMRC's cumulative method. A bonus makes your pay to date jump, so for that one payday more of your pay sits above the basic-rate band for that point in the year, and it is taxed at the higher rate.

Take £45,000 a year with a £5,000 bonus. Over the whole year the bonus costs £1,000 in income tax, which is 20%. But what payroll takes on the bonus payslip depends on the month:

• Paid in April, payroll takes £1,912 extra tax that payday (38.2% of the bonus).
• Paid in December, it takes £1,208 (24.2%).
• Paid in March, it takes £1,000 (20%), about what the year needs.

The extra comes back. In the December example, your later payslips take less tax: £87.94 less in month 10, £87.93 less in month 11, £32.13 less in month 12. So a bonus payslip that looks heavily taxed is mostly a matter of timing. The calculator shows both the payslip and the year, side by side.

This table is calculated by this page's own calculator. It assumes the 2026/27 tax year, England, tax code 1257L, paid in December, no student loan and no pension. Your payslip is final.

The share kept falls as the salary rises because more of the bonus lands in a higher band; on £100,000 the larger bonuses also reduce the personal allowance.

A tax code ending in W1, M1 or X is an emergency code. gov.uk says that on one, "your tax is worked out based on what you're paid in that week or month only". Each payday is taxed on its own, as if you were paid that amount every month of the year.

That is hard on a bonus. On £45,000 with a £5,000 bonus in December, an emergency code takes £2,452 on the bonus payslip, and later payslips are not adjusted. Over the year that is £908 more tax than the year needs. gov.uk says that if you have paid too much tax you can get a tax refund, and that HMRC will usually update your tax code once it has your details.

Your personal allowance goes down by £1 for every £2 of adjusted net income above £100,000, and is zero at £125,140 or more. In that stretch each extra pound of pay is taxed at 40% and also uses up allowance, so it is effectively taxed at 60%. With National Insurance at 2% on top, the effective rate on a bonus in that stretch is 62%.

Take £95,000 with a £15,000 bonus in March. You keep £6,700 of the £15,000 (44.7%). Payroll works from your tax code, which does not apply this reduction, so about £2,004 of the year's tax is not taken on your payslips. gov.uk says HMRC may send a Simple Assessment letter if you owe tax that cannot be taken out of your income.

Giving the whole bonus up for pension would change that. With the £15,000 sacrificed, take-home falls by £6,700 and £15,000 goes into the pension, and your income stays under £100,000, so £5,000 of personal allowance is given back. That is about 45p of take-home for each £1 in the pension.

National Insurance and student loan are worked out on each payday's own pay, not on the year. National Insurance is 8% of pay up to the period's upper limit (£4,189 in a month) and 2% above it. A bonus that takes a payday over that limit pays the lower rate on the part above it.

Student loan is the same: a percentage of that payday's pay above the loan's threshold. On £35,000 with Plan 2, a £3,000 bonus makes the bonus payslip repay £312 instead of the usual £42, which is £270 more over the year. See thestudent loan repayment calculator for the full picture of a loan.

On £45,000 with a £5,000 bonus in December, that payday's National Insurance is £343 instead of the usual £216: £126 more for the year, an effective 2.5% of the bonus.

With bonus sacrifice you agree to give up some or all of a bonus, and your employer pays that amount into your pension instead. The money never counts as your pay, so no income tax or employee National Insurance is taken on it, and your employer saves the National Insurance it would have paid. Some employers add that saving to the pension as well.

Take £60,000 with a £10,000 bonus in March, giving up £5,000. Your take-home falls by £2,900, because the £5,000 would have lost £2,100 to tax and National Insurance. £5,000 goes into the pension, so each £1 in the pension costs you about 58p of take-home. If the employer also adds its £750 National Insurance saving, £5,750 goes in and the cost drops to about 50p per £1.

Timing matters. HMRC's manual says entitlement to future pay "must be given up before it is treated as received". Its own example is an employee told of a £10,000 bonus on 31 August who gave it up by 30 September, before the 31 October payment, and could not change their mind. The employer paid £10,000 into a registered pension, and it was not taxed as the employee's income. A sacrifice agreed after the bonus is due does not work the same way.

From 2029, only the first £2,000 a year of pension salary sacrifice will stay free of National Insurance (HM Treasury and HMRC). The pension salary sacrifice calculator shows a regular sacrifice year by year.

If you or your partner get Child Benefit, a bonus that lifts the higher earner's income past £60,000 adds to the High Income Child Benefit Charge. On £55,000 with a £10,000 bonus and two children, the charge rises by £584.

Scotland has its own income tax bands. The same £4,000 bonus on £40,000 leaves £2,958 in Scotland and £3,069 in the rest of the UK.