UK Bonus Tax 2026/27 — Why Your Bonus Looks Over-Taxed (And Isn't)
Reviewed by Alex Morgan · Updated April 2026 · Annual bonus season explained for UK PAYE workers
Why your bonus payslip looks so brutal
PAYE works on a "cumulative" basis. Every month, HMRC's calculation is:
- Annualise the year-to-date pay (this month's pay × 12, plus prior months)
- Calculate the income tax and NI that would be due on that annualised amount
- Subtract the tax already paid in prior months
- The remainder is what's deducted from this month's payslip
Worked example: £35,000 salary, £10,000 bonus paid in March (month 12 of UK tax year):
Month 12 (March): £4,000 salary + £10,000 bonus = £14,000 gross
- YTD pay: £35,000 (11 months × £2,917) + £14,000 = £49,000 ⇒ within basic rate band
- YTD income tax due: (£49,000 − £12,570) × 20% = £7,286
- Tax already deducted in prior 11 months: £35,000 worth × 20% on £22,430 = ~£4,486
- March income tax deduction: £7,286 − £4,486 = ~£2,800 (most of the bonus stays!)
- NI deduction: £14,000 − £1,047 (monthly PT) = £12,953 × 8% = £1,036
- Net March pay: £14,000 − £2,800 − £1,036 = ~£10,164
- Effective tax+NI on the £10k bonus alone: ~28% — basic rate result, not 50%+
Compare to a higher earner's bonus paid mid-year — the "annualisation" effect is much harsher because the system thinks you'll earn at that elevated rate for the rest of the year. By March, the cumulative catch-up has fully corrected. Mid-year bonuses look more brutal than end-of-year bonuses even though the total annual tax is the same.
When bonuses really do hurt — the 60% trap
The genuine bonus tax horror story is the £100k–£125,140 personal allowance taper. Every £2 of income above £100,000 removes £1 of personal allowance, creating a 60% effective marginal rate. A bonus that pushes you across this threshold is taxed at 60% on the slice in this band. Worked example:
£95,000 salary + £20,000 bonus = £115,000 total income
- £95k → £100k slice of bonus: 40% income tax + 2% NI = 42% × £5,000 = £2,100
- £100k → £115k slice (in the 60% trap): 60% effective + 2% NI = 62% × £15,000 = £9,300
- Total tax + NI on £20,000 bonus: £11,400
- Net retained: £8,600 (43% of bonus)
The same £20k bonus paid to someone on £50k salary would attract roughly £8,400 in tax+NI (42% marginal). The £45k difference in pre-bonus salary creates a £3,000 difference in tax outcome — purely from the 60% trap mechanism. See the 60% trap explainer.
Bonus sacrifice — the cheat code
"Bonus sacrifice" or "bonus waiver" lets you redirect some or all of your bonus into your workplace pension before it's paid. Tax savings depend on your band:
| Income band | Tax + employee NI saved | Employer NI saved (often shared) | Net effective benefit |
|---|---|---|---|
| Basic rate (20%) | 28% | Up to 15% | Up to 43% |
| Higher rate (40%) | 42% | Up to 15% | Up to 57% |
| 60% trap (£100-£125k) | 62% | Up to 15% | Up to 77% |
| Additional rate (45%) | 47% | Up to 15% | Up to 62% |
Practical mechanics:
- Agree BEFORE the bonus is paid — once payroll has run, the chance is gone. Most employers run an annual sacrifice election in October/November before year-end bonuses.
- Annual Allowance check — make sure the sacrifice doesn't push your total contributions above the £60,000 AA (or your tapered AA if income above £260k adjusted). Carry-forward unused allowance from previous 3 years if needed.
- Employer NI saving — most progressive employers pass on at least part of their 15% NI saving as additional pension contribution. Always ask: "Will the employer NI saving be added to my pension contribution?"
- NMW floor still applies — sacrifice can't bring your base pay below £12.21/hour.
- Mortgage applications — most lenders use post-sacrifice gross. Time bonus sacrifice carefully if applying for a mortgage.
If you've already been "over-taxed" — fixing it
- Stay employed through the tax year — PAYE auto-corrects. By 5 April the cumulative deduction matches actual annual liability. Look at the year-end P60 to confirm.
- Leave the job mid-year — get a P45. The new employer continues from where you left off. If you're not working again that year, claim the over-payment via HMRC P800 or Self Assessment after year-end.
- Filed Self Assessment — the SA return reconciles your actual annual tax. Refund (or further bill) appears in the calculation. Pay or get refund via 31 January.
- Wrong tax code applied to bonus — if your tax code is wrong (e.g. emergency code, BR, 0T), contact HMRC on 0300 200 3300. Correct code retroactive to start of tax year if applicable.
Common bonus tax myths
- "Bonuses are taxed at 50%" — false. Bonuses are taxed at your marginal rate. The 50%+ deduction in month one is PAYE annualisation, not a special rate.
- "Take it as a gift to avoid tax" — illegal. Any cash from your employer is salary regardless of label. HMRC will reclassify and demand back-tax + penalties.
- "Pay it through a personal company" — IR35 / PAYE rules mean this is treated as employment income; gives no tax saving and creates fraud risk.
- "Spread the bonus across two months to avoid higher rate" — PAYE is annual; doesn't matter when in the year you receive it. Splitting only smooths cashflow, not annual tax.
- "Take it as shares to avoid tax" — RSUs and stock options have their own tax regimes (income on vest, CGT on sale). Often no actual saving vs cash; just deferral.
Pair this with
- → UK 60% tax trap 2026/27 — primary playbook for bonuses crossing £100k
- → UK salary sacrifice 2026/27 — companion strategy
- → UK Pension Annual Allowance 2026/27 — make sure you have AA headroom
- → UK Self Assessment 2026/27 — for reconciling over-deduction
- → UK Personal Allowance 2026/27
- → UK Take-Home Pay Calculator — model bonus impact