Got a bonus on the way? See exactly how much Income Tax and National Insurance comes off — and how much actually lands in your pocket. The calculator stacks the bonus on top of your salary to use the right marginal rate.
Bonus stacked on your salary · 2026/27
A bonus is treated as ordinary earnings, so it's taxed at your marginal rate — the rate on your next pound of income. The calculator works out your tax with and without the bonus, and the difference is the true tax on the bonus itself. That way the bonus is taxed at the right band, whether it stays in the basic rate or crosses into the higher rate.
National Insurance follows the same logic: 8% on the part of the bonus that falls below the £50,270 upper earnings limit, and 2% on anything above it.
On a £40,000 salary with a £5,000 bonus, your total of £45,000 is still inside the basic-rate band. The bonus is taxed at 20% (£1,000) plus 8% NI (£400), so you keep about £3,600. If your salary were £50,000, much of the same bonus would be taxed at 40%, and you'd keep far less.
| Salary | £5,000 bonus tax+NI | You keep |
|---|---|---|
| £30,000 | £1,400 | £3,600 |
| £40,000 | £1,400 | £3,600 |
| £55,000 | £2,100 | £2,900 |
| £110,000 | £3,000 | £2,000 |
In the month a bonus is paid, PAYE often over-taxes it because the system assumes you'll earn that much every month, briefly pushing you into a higher band. It usually corrects over the following months. The annual figure here is the real tax due. To see the impact on your overall pay, use the take-home pay calculator or check whether your salary plus bonus crosses the higher-rate threshold.
On a £5,000 bonus added to a £40,000 salary, you keep about £3,600. Roughly £1,000 goes in Income Tax at 20% and £400 in NI at 8%, since the total stays in the basic-rate band.
Only if it pushes part of your income above £50,270. A bonus is taxed at your marginal rate — the part that crosses into the higher band is taxed at 40%, the rest at 20%.
PAYE can over-tax a bonus in the month it's paid, assuming you'll earn that much every month. It usually corrects over later months. The annual figure here is the true tax due.
You can't avoid it, but paying the bonus into your pension via salary sacrifice removes Income Tax and NI on that amount, so it grows tax-free until you draw it.
