No. There is no separate rate of tax for a bonus: it is added to your pay for the year and taxed at whatever rate that pay has reached. On £45,000 a year, paid monthly, a £5,000 bonus adds £3,873.66 to your take-home pay in England, Wales and Northern Ireland, and £2,773.66 in Scotland, where income tax is devolved and the bands change at different points. The payslip in the bonus month still looks worse than either figure, because National Insurance is charged period by period and a cumulative tax code treats the spike as though it might carry on.
There is no bonus rate of tax
A bonus is earnings. It goes through PAYE with the rest of your pay, it is charged to income tax at the same band rates, and it attracts National Insurance in the same way. Nothing in the rules singles it out.
Because it sits on top of your salary, it is taxed at your highest rate rather than your average one. On £45,000 a year the next hundred pounds faces a combined rate of 28% in England, Wales and Northern Ireland, so you keep £71.96 of it. A Scottish taxpayer on the same salary faces 50% on it instead.
Over a whole year, on a monthly payroll in England, Wales or Northern Ireland, £45,000 takes home £35,920.08. With a £5,000 bonus, the gross is £50,000 and the take-home is £39,793.74, which is £3,873.66 more.
The pay period belongs in that sentence. National Insurance is charged on each month's pay in its own right, so the month a bonus falls in changes what the year costs, and a year divided by twelve does not answer the question.
Why the bonus month looks wrong
Two mechanisms pull in the same direction in a single pay period.
National Insurance is charged on the earnings of that period against thresholds set for that period. On a monthly payroll, the main rate of 8% applies between £1,048 and £4,189 for the month, and 2% above that. A bonus paid in one lump is charged at the main rate on the way up to the month's upper limit, and no later month gives any of it back.
Above that limit the rate falls, which cuts the other way. In this example an ordinary month pays £3,750.00 and £216.16 of National Insurance; the bonus month pays £8,750.00, of which the part above £4,189 is charged at 2% rather than 8%, so its National Insurance is £342.50. Over the year that comes to £2,720.26, and the bonus itself has cost £126.34 of National Insurance.
Income tax on a cumulative code recalculates the year to date each pay day. In the bonus month your year-to-date pay jumps, so the tax due on the year so far jumps with it, and the deduction that month is large. If your pay then returns to normal, the following months correct it: the year-to-date calculation notices that less tax is now due for the year and deducts less.
So the National Insurance on a bonus is genuinely final, and the income tax usually is not.
Unless your code is not cumulative
If your code ends in W1, M1 or X, the self-correction does not happen. Each pay period is taxed on its own, as though that month's pay were repeated all year, so a bonus can be taxed at rates your annual income never reaches.
That tax is not lost. It comes back when a cumulative code is applied, or after the tax year ends when HMRC reconciles the year. But it does not come back on its own within the month, which is why a bonus under an emergency code is the version people remember.
What a bonus does at a threshold
Only the part above a threshold is taxed at the higher rate. A bonus that carries you over £50,270 does not retax the pay below it; the excess is charged at 40% in England, Wales and Northern Ireland, and the rest is unchanged. Scotland runs more bands, at different points, and the section below gives them.
One threshold is different, and it is the one worth knowing about. Above £100,000 of adjusted net income the Personal Allowance falls by one pound for every £2 over that line, wherever in the UK you live. Losing allowance while paying the higher rate on the bonus itself produces an effective rate of 62% on that slice of income in England, Wales and Northern Ireland, and 69.5% in Scotland, until the allowance has gone entirely.
A bonus that lands across that line is therefore the one case where the marginal arithmetic is dramatic rather than mild, and it is worth working out before the payment rather than after.
Scotland is a different ladder
Income tax is devolved, so a Scottish taxpayer's bonus climbs a different set of bands. The Scottish higher rate of 42% begins at £43,662 of pay, below the point at which the rest of the UK reaches its higher rate, and an advanced rate of 45% sits above that.
On the example this page is built on, that is the whole of the difference. The same £5,000 bonus on the same salary adds £3,873.66 in England, Wales or Northern Ireland and £2,773.66 in Scotland, because more of the bonus meets a higher band.
National Insurance is not devolved. It is charged at the same rates against the same thresholds wherever in the UK you live, so everything on this page about the pay period, the bonus month and the upper earnings limit applies in Scotland unchanged.
What makes you a Scottish taxpayer is where your only or main home has been for most of the tax year, not where your employer is based. HMRC puts the S prefix on your tax code when its records say the Scottish rates apply to you.
Paying a bonus into a pension
Some employers let you give up a bonus for a pension contribution before you become entitled to it. Because the pay is never yours, it is not earnings, so neither income tax nor National Insurance is charged on it, and the employer's National Insurance is not charged either.
A cap on that National Insurance advantage has been announced for 6 April 2029, and our salary sacrifice guide carries what was announced and its source. It is announced rather than in force, and nothing on this site applies it to a 2026/27 figure.
That is a mechanism, not a recommendation. What it does to your take-home pay, your pension pot, your adjusted net income and any benefit that depends on your income are all different questions, and the answers differ by person. The rules also set annual limits on pension contributions that attract relief.
We explain what each choice does to the figures. For advice on whether a choice is right for you, a regulated financial adviser is the person to ask.
When a bonus is taxed
A bonus is taxed in the pay period in which it is paid, or earlier if you became entitled to it earlier. The timing matters at the edges of a tax year: a bonus paid on 1 April falls in a different tax year from one paid on 10 April, and if your income differs between the two years, so can the tax.
The decision about when a bonus is paid is your employer's. What you can do is check which tax year it lands in, because the whole calculation depends on the other income in that year.
When will the overpaid tax come back?
On a cumulative code, in your following payslips, without a claim. The payroll works out the year to date every pay day, so the correction is automatic once your pay returns to its usual level.
On a non-cumulative code, it waits for a cumulative code or for the year end. National Insurance charged in a bonus month is never revisited for an employee: the charge is settled on that month's pay and stays settled, whichever way it fell. That is the part of a bonus month that is genuinely final.