How UK Bonus Tax Works in 2026/27 (And Why It Feels So High)

Why bonuses feel highly taxed: the monthly aggregation method

When your bonus is paid, HMRC's PAYE system treats the income in that pay period as though it will repeat every month for the year. In the month a £5,000 bonus is paid on top of a £45,000 salary, payroll software treats that month's gross as £50,000 annualised (£45,000 + £5,000) and calculates income tax accordingly. This pushes a large slice of the bonus into the 40% higher rate tax band even if your total annual earnings remain within the basic rate.

The result is that you may pay more income tax on the bonus in the month it is received than you strictly owe for the year. However, this is not always wrong, if your total annual income genuinely crosses the higher rate threshold, the tax is correct and will not be refunded. If your total income stays below £50,270, the excess tax is usually corrected automatically through PAYE across the rest of the year, or via a P800 reconciliation letter after the tax year ends.

National Insurance compounds the effect. In the month of payment, your NI is calculated on the elevated gross. If your normal monthly salary is below the NI upper earnings limit (£50,270 / 12 = £4,189 per month) but the bonus pushes that month's gross above it, the portion above the UEL is taxed at only 2% NI rather than 8%, so NI is actually lower on the bonus slice than on regular salary. This is why a £5,000 bonus at a £45,000 salary does not lose 40% + 8% on the whole amount.

• PAYE annualises monthly gross: bonus month looks like a higher-salary month.
• Higher rate tax may apply to the bonus even if annual income is within basic rate.
• PAYE self-corrects during the year or via P800 if over-deducted.
• NI: bonus above monthly UEL equivalent is charged at only 2%, not 8%.

Strategies to reduce the tax impact of a bonus

The most tax-efficient strategy for most employees is directing the bonus into a pension via salary sacrifice before it is paid. Under salary sacrifice, the bonus never appears as PAYE income, it goes directly into your pension pot. A £5,000 bonus sacrificed into pension costs the employee nothing from their bank account and reduces their NI as well as income tax. The net cost to your pay of a £5,000 pension contribution when your marginal rate is 42% is just £2,900, your pension pot grows by £5,000 but your net pay only falls by £2,900.

Timing is a factor where you have any influence over it. If you are close to a threshold, such as £50,270 where higher rate starts, or £100,000 where Personal Allowance taper begins, receiving the bonus across two tax years can reduce the total tax liability. This requires agreement with the employer to defer part of the payment, which is not always possible but worth exploring for larger bonuses.

If your bonus pushes adjusted net income above £100,000, you enter the Personal Allowance taper zone where every £2 of additional income loses £1 of tax-free allowance, creating an effective 60% income tax rate. Pension salary sacrifice is particularly powerful here, a £10,000 pension contribution at this income level can restore the full Personal Allowance and save approximately £4,000 in income tax alone.

• Pension salary sacrifice: most efficient, removes bonus from PAYE entirely.
• Timing across tax years: effective if bonus can be deferred with employer agreement.
• Above £100,000: sacrifice to bring income below threshold restores Personal Allowance.
• Net cost of £1,000 pension at 42% marginal: £580. Net cost at 60% effective: £400.

When to expect a refund and when to act

If your bonus pushed you into a higher tax band temporarily but your total annual income remains within the basic rate, PAYE will typically self-correct. In subsequent months, your cumulative tax position is recognised and payroll deducts less, this process is automatic and usually completes before the tax year ends. You do not need to do anything unless it has not corrected by March.

If you are in self-assessment, because you earn above £100,000, have other income, or your employer uses a non-cumulative week-1/month-1 tax code, the reconciliation happens in your self-assessment return rather than automatically through PAYE. Keep your bonus payslip and confirm the year-end position when you submit your return.

If no automatic correction happens and you believe you have overpaid, contact HMRC after the tax year ends to request a P800 review. You can also check your personal tax account at gov.uk where HMRC shows your cumulative income tax position. Most genuine over-deductions from bonus months are corrected within the same tax year through the PAYE cumulative system.

• PAYE cumulative: usually self-corrects in months after bonus is paid.
• Month-1 code or self-assessment: no automatic correction, check your return.
• If undercorrected: request P800 review after tax year end.
• Check personal tax account at gov.uk for real-time cumulative position.