The 60% tax trap is not a conspiracy theory or an error. It's a mathematical certainty built into the UK tax system — and it affects anyone whose income crosses £100,000. Here's exactly how it works.
The Mechanics
The UK Personal Allowance (£12,570 tax-free) is not available to everyone. For incomes above £100,000, HMRC tapers the allowance away: for every £2 of income above £100,000, you lose £1 of Personal Allowance.
By £125,140, the Personal Allowance is completely gone.
Why This Creates a 60% Rate
If you earn £101,000, your allowance drops from £12,570 to £12,070. That £500 reduction means an extra £500 is suddenly taxable at 40% (£200 extra tax). Combined with the 40% tax on the £1,000 income above £100k (£400), and 2% NI (£20), you pay £620 in tax on £1,000 of income. That's a 62% effective marginal rate.
| Income | Extra £1,000 | Tax Paid | Effective Rate |
|---|---|---|---|
| £99,000 → £100,000 | £1,000 | ~£420 | 42% |
| £100,000 → £101,000 | £1,000 | ~£620 | 62% |
| £124,000 → £125,000 | £1,000 | ~£620 | 62% |
| £125,140 → £126,140 | £1,000 | ~£450 | 45% |
The Salary Sacrifice Solution
The most widely used tool to escape the 60% trap is pension salary sacrifice. If you earn £115,000, sacrificing £15,000 into your workplace pension brings your adjusted net income to exactly £100,000. You:
- Restore your full £12,570 Personal Allowance
- Avoid the 60% effective rate on £15,000
- Pay 40% less income tax (saving £6,000)
- Save 2% NI (saving £300)
- Add £15,000 to your pension
Net saving: over £6,000 in avoided tax. HMRC effectively pays 62% of your pension contribution in this zone.
Frequently Asked Questions
Is it legal to deliberately cut income to avoid the 60% trap?
Yes, completely legal. Salary sacrifice into a registered pension scheme is explicitly encouraged by HMRC. Even tax advisers call it "the most tax-efficient thing you can do if you earn between £100k and £125k."
What if I can't do salary sacrifice?
You can make personal pension contributions (not via salary sacrifice) and claim relief through Self Assessment. The mechanism is different, but the tax benefit is the same: your adjusted net income is reduced by the gross pension contribution.
Model the exact numbers with our £100k Tax Trap Calculator.