Calculator · 2026/27
Bonus tax calculator
A bonus sits on top of your salary, so it is taxed at your marginal rate — harder than your salary is on average. And because National Insurance is charged per pay period, the bonus month can take more NI than any annual calculation implies.
Your result
Worked example: a £5,000 bonus on £45,000
- Bonus, gross
- £5,000
- In your account
- £3,600
- 72.0% of it
- Tax and NI on it
- £1,400
- At a 28% marginal rate
- Employer NI on it
- £750
- Paid on top, invisible to you
Why the bonus month looks worse than this
Two separate things happen, and only one of them is a real extra cost.
Income tax usually self-corrects. PAYE is cumulative. A bonus can push one month's calculation into a higher band, and later months claw it back. Over the year the total is what this calculator shows.
National Insurance does not. It is assessed on each pay period separately, so a month whose earnings exceed one twelfth of the upper earnings limit pays 2% on the excess for that month, with no year-end correction. A large bonus in one month therefore genuinely costs more National Insurance than the same money spread over twelve. This is the one place where the annual figure on this site is a floor rather than the answer.
Sacrificing the bonus instead
Many employers will pay a bonus into your pension. Because it is sacrificed rather than paid, neither income tax nor either side of National Insurance is charged — so the full £5,000 lands in the pension instead of £3,600 landing in your account. Whether that trade suits you depends on when you need the money, but in a high marginal band the arithmetic is unusually one-sided.
Where £45,000 sits in the system
Every calculator on this site runs on the same thresholds, and the reason a figure surprises people is almost always that it sits near one of them. This is what is closest to the worked example above — the thresholds that decide what the next pound is worth, rather than what the last one was.
£45,000 sits between two things that matter. £11,205 below you is the Plan 4 (Scotland) repayment threshold, and £5,270 above you is the National Insurance upper earnings limit — so this salary is already past one change and approaching another.
| What changes | At | From here | |
|---|---|---|---|
| National Insurance upper earnings limit | £50,270 | +£5,270 | ahead |
| Higher rate | £50,271 | +£5,271 | ahead |
| Plan 4 (Scotland) repayment threshold | £33,795 | −£11,205 | passed |
Measured against the 2026/27 parameters for England, Wales & Northern Ireland. Distances are on gross pay before any salary sacrifice, because that is the figure every one of these thresholds is tested against.
- £50,270 — Above it your own National Insurance falls from 8% to 2%. That is £5,270 away, and it is the reason the higher rate stings less at the margin than the headline jump suggests.
- £50,271 — Crossing it does not re-tax what you already earn — only the pounds above it move to the higher rate, which is the single most misunderstood thing about UK income tax.
- £33,795 — Plan 4 (Scotland) takes 9% of the £11,205 above its threshold. It is not a tax, but it leaves the same pay on the same day.
What a ten per cent move would do
A swing of ten per cent either way from £45,000 does not cross a single band: the rate on further pay stays at 28% across the whole range from £40,500 to £49,500. That makes this an unusually predictable place to be paid, and it means the arithmetic below scales — a rise of any size in that range is worth the same proportion in your hand.
| If pay moved | Gross | Take-home | Change | Next £100 taxed at |
|---|---|---|---|---|
| −10% | £40,500 | £32,679.60 | −£3,240 | 28% |
| −5% | £42,750 | £34,299.60 | −£1,620 | 28% |
| +5% | £47,250 | £37,539.60 | +£1,620 | 28% |
| +10% | £49,500 | £39,159.60 | +£3,240 | 28% |
And what a pension contribution would buy
There is no threshold within reach below £45,000, so a pension contribution here is not about ducking under anything — it is simply the ordinary trade. Sacrificing £2,500 costs you £1,800 in take-home, because 28% of it was never going to reach you anyway, and puts the full £2,500 into the pot. That is £2,500 of saving for £1,800 of spending power — a ratio of 1.39 to one, and it is the same ratio for every pound until the next band.
Student loans on the same figure
A student loan is not a tax and it is not in any headline rate, but it leaves the same pay packet on the same day — so it belongs in any figure used to make a decision. This is what each plan takes at the worked example above.
Every one of the five repayment thresholds is behind this salary, so whichever plan you are on, you are repaying. Which plan you are on is not a choice, and the difference between them at this salary is £431.55 a year, so it is worth knowing which one your payslip is deducting.
| Plan | Starts at | Repaid a year | A month | Your next £100 |
|---|---|---|---|---|
| Postgraduate Loan | £21,000 | £1,440 | £120 | 34% |
| Plan 5 | £25,000 | £1,800 | £150 | 37% |
| Plan 1 | £26,900 | £1,629 | £135.75 | 37% |
| Plan 2 | £29,385 | £1,405.35 | £117.11 | 37% |
| Plan 4 (Scotland) | £33,795 | £1,008.45 | £84.04 | 37% |
A postgraduate loan is repaid alongside an undergraduate one rather than instead of it, so someone with both pays both.
One engine behind all eleven
Every calculator on this site runs the same tax engine, and the engine file your browser downloads is byte-identical to the one that generated these pages — a test asserts it, because two implementations of a tax rule is one too many. So the figures here cannot disagree with the salary tables, the hourly pages or any other calculator: they are the same arithmetic asked a different question. The method page sets out how the bands are discovered rather than typed, and sources lists every parameter with the government page and the date it was read from.
Questions people actually ask
How much tax will I pay on my bonus?
Your marginal rate, on the whole bonus. On £45,000 that is 28%, so a £5,000 bonus leaves £3,600. If the bonus pushes you into a higher band, the part above the threshold is taxed at the higher rate.
Why was my bonus taxed at 40% when I earn less than that?
Almost always a pay-period effect rather than the real rate. PAYE may treat the bonus month as though that were your normal monthly pay, taxing it as if you earned twelve times as much. Income tax is cumulative, so later months correct it. National Insurance does not correct, and that part is genuinely permanent.
Can I put my bonus into my pension to avoid tax on it?
If your employer offers bonus sacrifice, yes — the bonus is never paid as earnings, so no income tax and no National Insurance is due on either side. It is deferred rather than avoided: it is taxed when you draw the pension, usually at a lower rate and with 25% typically tax-free.
What this calculation assumes
- 2026/27 rates for England, Wales & Northern Ireland.
- One employment, paid through payroll, taxed on the standard code with no adjustments carried in.
- Employment income only — no dividends, savings interest, rental or self-employment income.
- No taxable benefits in kind, no company car, no unpaid leave.
- National Insurance category A: the standard case for an employee over 21 and under State Pension age.
- Income Tax is annual, but National Insurance is charged per pay period — a large one-off bonus can pay more NI than this annual view shows.
- No student or postgraduate loan repayment.
- No salary sacrifice and no workplace pension contribution.