UK Bonus Tax Explained 2025/26 — Why 60% Effective Rate & How to Mitigate

1. Why bonus tax feels brutal

A bonus is just another lump of employment income — the same rules apply as for your salary. What changes is its position in your stack of income for the year. Because the bonus is paid on top of your normal pay, every pound of it is taxed at your marginal rate, the rate that applies to your highest band. If your salary already takes you into the higher-rate band, the entire bonus is taxed at 40% (or 42% in Scotland). If it pushes you across a threshold, part of it is taxed at the lower rate and the rest at the higher.

On top of the headline income tax sit National Insurance and, if applicable, a student loan deduction. And in the month the bonus is paid, PAYE often appears to deduct even more than your true annual liability — because the payroll system temporarily projects an unrealistic annual figure from a single chunky payslip. The end-of-year reconciliation corrects this, but the bank balance shock is real.

2. Standard bonus taxation 2025/26 (rest of UK)

For employees living outside Scotland, the bonus is taxed at your marginal rate within each band:

Add a student loan deduction (9% Plan 1/2/4/5, 6% Plan 3 — Postgraduate) on top if applicable. A higher-rate-band bonus for a Plan 2 graduate therefore loses 42% + 9% = 51% at source. Inside the taper trap, the same graduate loses 62% + 9% = 71%.

3. The £100k–£125,140 personal allowance taper trap

The personal allowance (£12,570 in 2025/26) is withdrawn at the rate of £1 for every £2 of adjusted net income above £100,000. By £125,140, the allowance has been withdrawn entirely.

The arithmetic of the trap: when income rises by £2 within the taper band, your taxable income rises by £3 — the £2 itself, plus £1 of allowance that has been pulled into charge. That extra £3 is taxed at 40%, producing £1.20 of tax on £2 of pay. Effective income-tax marginal rate = £1.20 / £2 = 60%. Add 2% NI = 62%. Add a 9% student loan = 71%.

What makes this trap so dangerous is that it is invisible on the payslip. PAYE adjusts your tax code so the deductions look smooth, but the underlying liability is brutal.

4. Scotland: 67.5% taper trap

Scotland sets its own income-tax rates and bands (NI remains UK-wide). In 2025/26, Scottish higher rate is 42% on income between £43,663 and £75,000, advanced rate 45% from £75k–£125,140 and top rate 48% above £125,140. The personal allowance is reserved to Westminster and still tapers by £1 for £2 above £100k. Inside the taper, the lost allowance is now taxed at 45% (advanced rate), giving an effective income-tax marginal rate of 45% × 1.5 = 67.5%. Plus 2% NI = 69.5%. A Scottish Plan 2 graduate in the taper sees 78.5% of each marginal pound disappear.

5. Worked example — £30,000 bonus on a £95,000 salary (rUK)

The exact figures vary with rounding and with how PAYE assigns the bonus across pay periods, but the principle is robust: a bonus that lands inside the £100k–£125,140 corridor is the most heavily taxed pound of income in the UK system.

6. The PAYE emergency-month effect

Payroll systems calculate tax cumulatively (or in some cases on a Month 1 basis). When a one-off bonus is paid, the system can project the bonus across the rest of the year, briefly applying higher rates of tax to ensure HMRC is not under-paid. A £30,000 bonus paid in month 6 may briefly be treated as part of an annualised £180,000+ income, dragging some of it into the 45% additional rate within that month's PAYE calculation.

The good news: this is self-correcting. Each subsequent month, the cumulative calculation pulls the average back down, and by year-end (or as the P60 is issued) you will have paid exactly the right amount. The bad news: cash flow is unpleasant, and any small employer running PAYE on a Month 1 code (common in the first year of employment, for example, until a P45 is fully processed) may require an explicit reconciliation request to HMRC.

7. Mitigation: bonus sacrifice into a pension

The single most powerful mitigation route is to give up the cash bonus before entitlement arises in exchange for an employer pension contribution. Because the money never reaches you as pay:

• No income tax — saves 20% / 40% / 45% (or Scottish equivalents) at your marginal rate, or up to 60–67.5% if you would otherwise have been in the taper.
• No employee National Insurance — saves 8% on basic-rate slice, 2% above.
• Your employer saves 15% employer NI on the sacrificed amount. Many employers add some or all of that saving to your pension contribution (often a 100% pass-through, sometimes a 50:50 split).
• If sacrifice keeps your adjusted net income below £100,000, you restore your full personal allowance and avoid the taper entirely.
• If sacrifice keeps you below £60,000 of adjusted net income, you avoid the High Income Child Benefit Charge if eligible.

For our £30,000 bonus on top of £95,000 salary example: sacrificing the entire £30,000 into the pension costs you £0 in immediate tax — and the pension fund receives £30,000 plus (potentially) £4,500 of shared employer-NI saving. Compare that with the £12,400 net you would otherwise have taken home, and the pension route delivers more than double the long-term wealth, with the additional benefit of tax-free investment growth inside the wrapper.

8. Mitigation: Payroll Giving

Payroll Giving (sometimes called Give As You Earn, or GAYE) lets you donate to UK-registered charities directly from your gross pay, before income tax is calculated. A higher-rate taxpayer donating £30,000 sees the charity receive the full £30,000 at an effective personal cost of just £18,000 (i.e. £30,000 less the 40% income tax that would otherwise have been paid). Inside the £100k–£125,140 taper band, the effective cost drops to £12,000 (60% relief).

Payroll Giving does not save employee NI — only income tax. It also does not earn the employer-NI saving that pension sacrifice does. But for taxpayers who want to make a charitable donation anyway, it is the most efficient single route.

9. Mitigation: Gift Aid (after the fact)

If your bonus has already landed in your bank account net of PAYE, a Gift Aid donation can still recover some of the tax. The mechanics differ from Payroll Giving:

• You donate net; the charity reclaims basic-rate tax (currently grossing up by 25%, equivalent to 20% of the gross). A £80 donation becomes £100 in the charity's hands.
• If you are a higher-rate taxpayer, you claim the difference between basic and higher rate (i.e. an extra 20% of the gross amount) through your Self Assessment return, reducing your personal tax bill.
• For taxpayers in the £100k–£125,140 taper, Gift Aid donations also reduce adjusted net income, restoring some of the personal allowance — so the relief stacks at the 60% effective rate.

Gift Aid is slightly less efficient than Payroll Giving (because the basic-rate tax goes to the charity not you), but it works retrospectively: a donation made before 31 January following the tax year can be carried back into the prior year's SA return.

10. The bigger pension planning picture

Beyond the immediate bonus, pension contributions (sacrificed or relief-at-source) can be used to engineer adjusted net income downwards. Two threshold values to target:

• £100,000: dropping below this restores the full £12,570 personal allowance, escaping the 60% taper trap entirely.
• £60,000: dropping below this preserves the full High Income Child Benefit (subject to the partner's income too).

Note the £60,000 standard annual allowance limit on pension contributions, plus the tapered annual allowance for very high earners (kicking in where adjusted income exceeds £260,000). For high earners, the carry-forward rules allow unused allowance from the previous three tax years to be used in the current year — a useful lever when an unusually large bonus arrives.

11. Family and IHT planning angles

Once the bonus has been taxed and is in your hands, the residue can still be planned. Common routes:

• Spouse transfer: gifts between UK-domiciled spouses or civil partners are exempt from IHT and trigger no CGT. Investing the net bonus in your spouse's name routes future income and gains through their (often lower) personal tax bands and allowances.
• Junior ISAs / pensions for children: up to £9,000 per child per year into a JISA, up to £2,880 net (£3,600 gross) into a Junior SIPP — all tax-free growth.
• Gifts to adult children: £3,000 per year is immediately IHT-exempt under the annual exemption; larger gifts become potentially-exempt transfers and fall outside your estate after 7 years (with taper relief on a sliding scale from year 3).
• Surplus income gifts: regular gifts out of post-tax income that do not affect your standard of living are immediately exempt — useful for sustained giving from an annual bonus pattern.

12. Worked mitigation example — sacrifice vs no sacrifice

13. Official references

For the underlying rules, consult HMRC's own guidance:

• Personal allowance taper: Income Tax Act 2007 s.35, summarised in HMRC manual PIM (Personal Allowances) and at gov.uk "Income Tax rates and Personal Allowances".
• Salary sacrifice rules: HMRC Employment Income Manual EIM42750 et seq.
• Payroll Giving: ITEPA 2003 ss.713–715; HMRC guidance at gov.uk/payroll-giving.
• Gift Aid: HMRC Chapter 3 Part 8 ITA 2007; SA reclaim via SA100 box 5.
• Scottish income tax bands: Scotland Act 2016, annual Scottish rate resolution; current tables on gov.scot.
• HICBC: Finance Act 2012 Sch. 1; reformed thresholds from 6 April 2024.

Bonuses are not, in themselves, taxed punitively — but the place they land in your income stack often is. Knowing the bands you are crossing, and using the legitimate sacrifice and giving mechanisms available to you, is the difference between losing 60p of every marginal pound and keeping the lot working for you.