How are Bonuses Taxed in the UK? A Complete Guide to PAYE Bonus Tax

Receiving a workplace bonus is always cause for celebration, but seeing the subsequent payslip can often lead to a sense of disappointment. Many employees find that their bonuses are taxed at what feels like a disproportionately high rate compared to their regular monthly salary. In the 2026/27 UK tax year, bonuses are fully subject to Income Tax and National Insurance Contributions (NICs). Understanding the mechanics of PAYE (Pay As You Earn) payroll systems is essential to decoding why your bonus deductions look the way they do and how your final tax liability is determined.

Why is My Bonus Taxed So Heavily?

The primary reason a bonus seems taxed more heavily on your payslip is due to the way payroll software operates. In the UK, PAYE uses tax codes to spread your personal tax-free allowance (£12,570 for a standard 1257L code) evenly across the pay periods of the tax year. When a one-off lump sum is processed, the payroll system often calculates deductions as if you will earn that combined amount every single month of the year. This can temporarily push you into a higher tax bracket (e.g., from the 20% basic rate to the 40% higher rate or 45% additional rate) for that specific pay cycle.

However, it is important to understand that Income Tax is a cumulative annual calculation. If too much tax is deducted in the month you receive your bonus, the PAYE system will naturally self-correct in subsequent months, or you will receive a tax refund after the end of the tax year when HMRC calculates your final annual earnings.

Income Tax Bands and Rates for 2026/27

Your bonus is added to your regular earnings and taxed according to the standard UK Income Tax bands. For the 2026/27 tax year, the bands for residents in England, Wales, and Northern Ireland are structured as follows:

Note: The Personal Allowance is tapered for individuals with an adjusted net income exceeding £100,000, which creates a marginal tax rate of 60% in that specific band. We cover this in detail in our dedicated £100k tax trap guide.

National Insurance Contributions on Bonuses

Unlike Income Tax, National Insurance Contributions (NICs) are calculated on a non-cumulative basis. This means each pay period stands completely alone. The rates and thresholds used depend entirely on the earnings in that specific period. For employees in 2026/27, the main Class 1 NIC rates are:

• Main Rate (8%): Applied to weekly earnings between £242 and £967 (or monthly equivalent between £1,048 and £4,189).
• Upper Rate (2%): Applied to weekly earnings above £967 (or monthly equivalent above £4,189).

When you receive a bonus, it is added to your salary for that month. Because NICs are non-cumulative, any earnings that exceed the Upper Earnings Limit (£4,189 monthly) will only incur NICs at the 2% rate. This means that while a bonus may face higher Income Tax rates, the percentage of National Insurance deducted on the lump sum might actually decrease if it pushes your monthly pay above the Upper Earnings Limit.

Step-by-Step Payroll Calculation Example

Let us look at a practical example of a monthly salaried employee receiving a bonus in the 2026/27 tax year:

• Regular Monthly Salary: £3,500 (Gross annual equivalent of £42,000)
• One-Off Bonus: £5,000
• Total Gross Pay for the Month: £8,500

On a standard monthly pay cycle, the PAYE system treats the £8,500 gross pay as follows:

1. Tax-free Allowance Allocation: 1/12th of £12,570 (£1,047.50) is protected from Income Tax.
2. Basic Rate Band Allocation: The remaining basic rate band for the month is roughly £3,141.67 (taxed at 20%).
3. Higher Rate Band Allocation: The portion of the monthly pay exceeding £4,189.17 (£8,500 – £1,047.50 – £3,141.67 = £4,310.83) is taxed at the higher rate of 40%.
4. National Insurance: The employee pays 8% NICs on earnings between the primary threshold and Upper Earnings Limit, and 2% NICs on the balance above £4,189.

Frequently Asked Questions: PAYE Bonus Tax

1. How much tax do you pay on a bonus in the UK?
Your bonus is taxed at your highest marginal rate of Income Tax, which is either 20%, 40%, or 45% depending on your total annual earnings. In addition to Income Tax, you will also pay employee National Insurance Contributions of either 8% or 2% on the bonus amount.

2. Why is my bonus taxed at 40% when my normal tax rate is 20%?
Your bonus is taxed at 40% on your payslip because the PAYE system processes the lump sum as if you earn that higher amount every month. This temporary calculation pushes your monthly earnings above the higher-rate threshold, but HMRC adjusts this over the year.

3. Will I get a tax refund if my bonus was overtaxed?
Yes, you will automatically get a refund if the PAYE system overdeducts tax on your bonus. The system will adjust your tax deductions in the subsequent months of the tax year, or HMRC will issue a tax calculation (P800) and refund after the year ends.

4. Do you pay National Insurance on bonuses in the UK?
Yes, bonuses are fully subject to Class 1 National Insurance Contributions. The deduction is calculated on your combined monthly salary and bonus, using the standard rates of 8% on earnings up to the Upper Earnings Limit and 2% above it.

5. Is National Insurance on bonuses cumulative?
No, National Insurance is non-cumulative and calculated on a pay-period by pay-period basis. Each month’s deductions are finalized independently, meaning you benefit from the lower 2% rate on any portion of your bonus that exceeds the monthly Upper Earnings Limit.

6. What tax code is used for bonuses?
Your employer will use your active tax code (such as 1257L) to calculate tax on your bonus. If you receive a bonus under a temporary or emergency code like BR, your entire bonus will be taxed at the flat basic rate of 20% without any personal allowance.

7. How can I estimate my net take-home pay on a bonus?
You can estimate your take-home pay by adding your bonus to your regular salary and applying your marginal tax and NIC rates. For a precise calculation that accounts for all deductions, use our online Bonus Tax Calculator.

8. Do student loan deductions apply to bonuses?
Yes, student loan repayments are deducted from bonuses if your total gross earnings in that pay period exceed the threshold. Repayments are calculated at 9% on earnings above the threshold for Plan 1, Plan 2, Plan 4, or Plan 5, and 6% for Postgraduate plans.

9. Does my employer pay tax on my bonus?
Yes, your employer must pay Class 1 Secondary National Insurance Contributions on your bonus. For the 2026/27 tax year, the employer National Insurance rate is 15.0% on earnings above the secondary threshold.

10. Is a sign-on bonus taxed differently?
No, a sign-on bonus is treated as standard employment income by HMRC. It is processed through PAYE and subjected to the same Income Tax, National Insurance, and pension rules as regular performance-related bonuses.