The £100,000 Tax Trap: How the 60% Rate Works (and How to Escape It)
Few people expect a pay rise to be taxed at more than the headline 45% top rate. Yet there is a band of income — between £100,000 and £125,140 — where every extra pound is effectively taxed at 60%. It is one of the quirks of the UK system, and one of the easiest to plan around once you understand it.
What is the £100,000 tax trap?
Everyone gets a personal allowance — £12,570 of income taxed at 0%. But once your adjusted net income (broadly, your taxable income after pension contributions and Gift Aid) rises above £100,000, that allowance is withdrawn at a rate of £1 for every £2 you earn over the limit. By £125,140 it has disappeared completely.
Why it's 60%, not 40%
Here is the arithmetic for a higher-rate taxpayer in this band. Earn one extra pound and two things happen:
- That pound is taxed at the 40% higher rate — so 40p goes in tax.
- You also lose 50p of personal allowance. That 50p, which used to be tax-free, is now taxed at 40% too — another 20p.
Add them together and you keep just 40p of your extra pound — a 60% effective tax rate. Factor in 2% National Insurance and the true marginal rate is 62%. The effect is purely within the band: below £100,000 you are on 40%, and above £125,140 (allowance fully gone) you drop back to the 45% additional rate.
Your marginal tax rate by income (2026/27, rest-of-UK, before National Insurance). The personal-allowance taper creates a 60% spike between £100,000 and £125,140 — steeper than the 45% rate that applies above it.
It can be even worse if you have young children
For parents of pre-school children in England, £100,000 is a second cliff edge: crossing it also removes eligibility for funded childcare hours and the Tax-Free Childcare top-up. Those can be worth thousands of pounds a year, which means a modest pay rise above £100,000 can genuinely leave a family worse off than before. If that is you, keeping your adjusted income under £100,000 matters even more — check the current childcare rules on GOV.UK.
How to escape it: pay into your pension
Because the trap is measured on adjusted net income, anything that reduces that figure pulls you back out — and pension contributions are the main lever. Sacrifice or contribute enough to bring your adjusted income down to £100,000 and your full allowance is restored.
The striking part is how cheap this is. Take someone earning £110,000 who pays £10,000 into their pension by salary sacrifice, bringing their adjusted income to £100,000:
In other words, £10,000 lands in their pension for a real cost of just £3,800 — an effective rate of 38%. Put the other way round, every £1 they sacrifice in this band costs them only 38p of take-home. There are very few places you will find a return like that.
Every £1 you redirect into a pension in the £100k–£125k band costs you just 38p of take-home — and rescues your personal allowance on the way.
What actually lowers your adjusted net income
The trap is measured on adjusted net income, so only things that reduce that figure pull you out. Plenty of sensible money moves don't touch it at all:
Lowers it (escapes the trap)
- Pension contributions — salary sacrifice or a personal contribution
- Gift Aid donations to charity
- Sacrificing a bonus before it's paid
- Cycle-to-work / EV salary-sacrifice schemes
Doesn't change it
- ISA contributions — no income-tax relief
- Overpaying your mortgage
- Your partner's pension — it's tested on you alone
- Moving cash between savings accounts
Scotland: the trap is even steeper
The personal-allowance taper is UK-wide, but Scottish taxpayers face the 45% advanced rate in this band rather than 40%. The same allowance-withdrawal mechanism then produces an effective rate of around 67.5% before National Insurance — making pension contributions in this band even more worthwhile.
The bottom line
If your income sits between £100,000 and £125,140, the 60% band is real but eminently avoidable. A pension contribution that brings your adjusted income back to £100,000 restores your allowance, builds your retirement pot, and costs far less than the headline figure suggests. Work out your own number before deciding how much to pay in.
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Common questions
Sources
GOV.UK — Income Tax rates & Personal Allowance and GOV.UK — adjusted net income. See our full methodology and rates.
This article is general information for the 2026/27 tax year and not personalised financial advice. Check your own loan details in your student loan account and verify figures against GOV.UK before making decisions.