The 60% Tax Trap Between £100k and £125k for High Earners

Between £100,000 and £125,140 of income, the UK quietly withdraws your personal allowance, creating an effective marginal rate of roughly 60% on that slice of earnings. This is the 60% trap high earners keep stumbling into: cross £100k and every extra pound is taxed far harder than the headline 40% rate suggests.

What the 60% tax trap actually is

Most people assume the tax system gets gentler as bands widen, not sharper. Yet there is a stretch of income where the opposite happens. Once your income passes £100,000, HMRC starts clawing back the tax-free personal allowance of £12,570 at a rate of £1 for every £2 you earn above that threshold. By the time your income reaches £125,140, the allowance has vanished entirely.

Losing that allowance is not free. Income that was previously untaxed becomes taxable at 40%, on top of the 40% you already pay on the earnings themselves. The published Income Tax rates and bands never mention 60% anywhere, which is exactly why so many people are caught off guard. The figure that matters here is not your salary but your adjusted net income — broadly your total taxable income after pension contributions and Gift Aid, which is the number that actually triggers the taper.

What makes this so easy to miss is timing. Payroll deducts tax evenly across the year on the assumption that your circumstances stay constant, so the extra bite from a bonus or a mid-year pay rise often shows up only when HMRC reconciles the year or your tax code changes. Someone who moves from £95,000 to £110,000 does not see a neat 40% deduction on the extra £15,000; a large slice of it is taxed at the punishing effective rate instead. Interest, dividends, rental profits, and taxable benefits in kind all feed into the same adjusted net income calculation, so it is surprisingly common to drift over £100,000 without a single change to your basic salary.

Why the 60%taxp high earners face is not a headline rate

The reason the 60% trap high earners encounter feels invisible is that it never appears on a payslip or a rate card. It is an emergent effect of two rules colliding: the 40% higher-rate band and the withdrawal of the allowance. To see it clearly, follow a single extra £1,000 earned inside the band. We explain the mechanics in more depth in our guide to the personal allowance taper, but the worked figures below make the sting obvious.

Extra £1,000 earned between £100k and £125,140

Amount

Additional income

£1,000

Income Tax at 40%

£400

Personal allowance lost (£1 for every £2)

£500

Extra income is now taxed at 40% because the allowance is gone

£200

Total tax on that £1,000

£600

Effective marginal rate

60%

Only £400 of every £1,000 lands in your pocket. Push a little further, and it gets worse: add employee National Insurance and, for parents, the loss of childcare support, and the real cost of that income can exceed 60%. You can cross-check the underlying thresholds against HMRC's official rates and allowances tables, which are frozen until at least April 2031 — meaning wage growth pulls more people into this band every year.

Scotland: the trap bites even harder

Because Scotland sets its own income tax rates, the band between £100,000 and £125,140 falls within the Scottish advanced rate of 45%. Combine that 45% with the allowance withdrawal,l and the effective marginal rate climbs to around 67.5% — noticeably steeper than the rest of the UK. If you are a Scottish taxpayer, review the current Scottish income tax position and our dedicated note on Scottish income tax before assuming the standard 60% figure applies to you.

The hidden cliff-edges beyond the tax itself

The percentage is only part of the pain. Crossing £100,000 of adjusted net income also switches off benefits unrelated to income tax. In England, both the free childcare hours and Tax-Free Childcare are lost the moment either parent's adjusted net income exceeds £100,000. For a family with two young children in nursery, that withdrawal can be worth thousands of pounds a year — a genuine cliff-edge rather than a gentle taper. A modest pay rise or bonus that nudges you over £100k can, absurdly, leave you worse off overall.

Because these childcare rules use the same adjusted net income measure as the taper, the tools that fix your tax position tend to fix your childcare position at the same time. Bringing your figure back under £100,000 through pension contributions or Gift Aid can restore both the allowance and childcare support, which is why parents in this band often have the strongest case for acting. The cliff-edge cuts both ways: the same £1 that costs you the support can, with planning, win it straight back.

How to escape the trap: pensions, Gift Aid and salary sacrifice

The good news is that the taper is driven by adjusted net income, which you can influence. The 60% trap that high earners fall into is also why pension contributions are so powerful in this band: relief is effectively given at the same 60% rate.

Pension contributions

A personal or workplace pension contribution reduces your adjusted net income pound for pound. Put £1,000 into a pension from income sitting inside the trap, and it costs you roughly £400 net once the 60% relief is accounted for — you are, in effect, moving money from the taxman into your own retirement pot at a discount. The mechanics of higher-rate and taper relief are set out in HMRC's guidance on pension tax relief, and we cover the cross-border angle in pension contributions for US-UK filers.

Gift Aid donations

Charitable donations made under Gift Aid work in the same direction. The grossed-up donation reduces your adjusted net income, so a well-timed gift can pull you back below £100,000 or £125,140 and restore some or all of your allowance while supporting a cause you care about.

Salary sacrifice and timing

Many employers let you exchange salary for benefits such as extra pension, an electric car, or the cycle-to-work scheme through salary sacrifice, which lowers your taxable pay directly. If a bonus is what tips you over £100k, ask whether it can be sacrificed to a pension or deferred to a year when your income is lower. Small timing decisions around bonuses and dividends can be the difference between paying 40% and paying 60%.

The US-UK twist: don't just shift your tax to the IRS

For Americans living in Britain, the 60% trap high earners face carries a second layer that catches even careful planners out. Reducing your UK tax bill is only half the equation, because you still have to file a US return, and the two systems interact in ways that can quietly cancel out your savings.

The core issue is the US foreign tax credit. Dual filers usually rely on the UK tax they pay to offset the US tax due on the same income, claimed on Form 1116. If you slash your UK tax with a large pension contribution, you reduce the very credit you were banking on — potentially leaving more income exposed to US tax. In some cases, you save 60% in the UK only to hand a chunk of it back to the IRS, so the net benefit is far smaller than the headline suggests. Our walkthrough of the foreign tax credit on Form 1116 shows how the credit is limited.

Pension treatment adds further complexity. A UK workplace pension may be protected under the US-UK tax treaty, but US contribution limits and the treatment of employer contributions differ from the UK rules. Hence, a strategy that is efficient for HMRC is not automatically efficient for the IRS. The practical rule for dual filers is simple: model the UK saving and the US result together, never in isolation.

Worked case study: Priya, £118,000, dual US-UK filer

Priya is a US citizen working as a technology director in London on a base salary of £118,000. That places £18,000 of her income squarely in the trap, where the 60% rate high earners experience is costing her around £10,800 in tax and lost allowances on that slice alone. She and her partner have also lost their Tax-Free Childcare, worth roughly £2,000 a year, because her adjusted net income sits above £100,000.

By making an £18,000 personal pension contribution, Priya brings her adjusted net income back to £100,000. She recovers her full personal allowance, wins back the childcare support, and secures around 60% combined tax relief — a net cost of roughly £7,200 for £18,000 in her pension.

Before finalizing, her adviser models the US side: the lower UK tax reduces her available foreign tax credit, so part of the income shifts into the US net. After factoring that in, the plan still leaves her substantially ahead. Still, the optimal contribution is £18,000 precisely because it was tested against both tax systems rather than the UK figure alone.

Talk to TaxYork about escaping the trap.

If your income sits between £100,000 and £125,140 — especially if you file on both sides of the Atlantic — the right contribution is the one modeled against both HMRC and the IRS. Email hello@taxyork.com, call 020 3488 8606, or visit taxyork.com to arrange a cross-border review before your next bonus or tax year-end.