The UK £100K Tax Trap: The 60% Rate Nobody Warned You About

Ask most UK employees what the top rate of income tax is and they will say 45%. The real answer, for a growing slice of the workforce, is 60% — plus National Insurance. It applies not to millionaires but to anyone earning between £100,000 and £125,140, and it is written into no tax band table you will ever see on a payslip. Welcome to the £100K tax trap.

How the trap works

The mechanism is the withdrawal of the personal allowance — the £12,570 you normally earn tax-free:

• Above £100,000 of adjusted net income, you lose £1 of personal allowance for every £2 earned.
• Each extra £1 in the zone is therefore taxed at 40% and drags another 50p of previously tax-free income into the 40% band. That is 40% + 20% = 60% effective tax on every pound.
• Add 2% employee National Insurance and the true marginal rate is 62%.
• The trap zone runs from £100,000 to £125,140 — the point at which the allowance is fully gone. Above it, the marginal rate actually falls to 47% (45% additional rate + 2% NI).

The absurd result: someone on £120,000 faces a higher marginal tax rate than someone on £220,000.

Two details worth knowing. First, the trap is triggered by adjusted net income (ANI) — broadly, total taxable income minus pension contributions and grossed-up Gift Aid — not your headline salary. Bonuses, rental income, taxable benefits and savings interest all count towards the £100,000. Second, in Scotland the band structure differs (the trap runs at roughly 69.5% including the 45% advanced rate), but the personal allowance taper is UK-wide: nobody north of the border escapes it either.

What you actually keep

These take-home figures come from our UK salary calculator for the 2026/27 tax year (England, Wales and Northern Ireland, no pension or student loan):

Click any salary in the table for the full breakdown — income tax, National Insurance, monthly and weekly figures. Notice how flat the take-home curve is through the trap zone: £25,000 of extra gross between £100,000 and £125,000 turns into barely £12,000 of extra net.

Why more people fall in every year

The £100,000 threshold has been frozen since it was introduced in 2010. Had it risen with inflation, it would sit at roughly £150,000 today. Instead:

• The Autumn Budget 2025 confirmed income tax thresholds stay frozen until April 2031.
• Fiscal drag does the rest: the OBR projects 4.8 million more higher-rate taxpayers by 2030/31 as wages grow into frozen bands.
• What was designed as a tax on the top 1% now routinely catches senior engineers, doctors, and London professionals with ordinary pay progression.

The NHS knows this problem well: consultants have famously declined extra shifts because the marginal maths made overtime barely worthwhile. The same logic now applies across the private sector — which is why understanding your position in the band, rather than your headline salary, matters more with every pay review.

Three legal escapes

1. Pension contributions via salary sacrifice. Sacrificed salary reduces your adjusted net income (ANI). Drop below £100,000 and your personal allowance is fully restored — meaning every pound sacrificed in the trap zone gets effective relief of 60%+. It is the single most efficient pension saving available in the UK. Note the window is narrowing: from April 2029, NIC relief on salary sacrifice is capped at £2,000 per year, though the income tax mechanics remain.
2. Gift Aid donations. Charitable gifts reduce ANI by the grossed-up amount — the same allowance-restoring mechanism, if giving is already part of your plans.
3. Timing bonuses. If a bonus would push a single year over £100,000, deferring it into a year where your total stays under the threshold avoids the 60% band entirely. Many employers allow bonus deferral into pension for exactly this reason.

The childcare cliff on top

For parents, the trap has a second, sharper edge. At £100,000 of adjusted net income you lose — in full, not tapered — both tax-free childcare (worth up to £2,000 per child per year) and the 30 free hours of childcare for under-5s. A £1 pay rise past £100,000 can cost a family with two young children more than £2,500 a year in withdrawn support. For that pound, the effective tax rate is over 100% — you are genuinely poorer for being paid more. Pension contributions that bring ANI back under £100,000 restore childcare eligibility too, which is why accountants call this the most valuable pension nudge in the tax code.

Frequently asked questions

At what salary do I lose my personal allowance completely?

£125,140. At £1 lost per £2 over £100,000, the full £12,570 allowance is gone once you earn £25,140 above the threshold.

Is £101,000 worth less than £99,000?

For parents relying on childcare support: potentially yes — the withdrawn childcare benefits can exceed the extra pay. For everyone else, no: you always keep something, but of that extra £2,000 you net only around £760 after the 62% marginal rate.

Do pension contributions restore my personal allowance?

Yes. What counts is adjusted net income, not gross salary. Pension contributions (and Gift Aid) reduce ANI pound for pound — bring it below £100,000 and the allowance, and any childcare eligibility, come back.