UK £100k Tax Trap Calculator – Personal Allowance Withdrawal 2025/26
Use this UK £100k Tax Trap Calculator to estimate how your Personal Allowance changes when your adjusted net income goes above £100,000. Enter your annual salary, bonus, current pension or salary sacrifice, and any extra planned contribution to see whether you are inside the personal allowance taper zone and how much it is costing you.
The calculator estimates your adjusted net income, Personal Allowance remaining, allowance lost, income tax, National Insurance, take-home pay, and the extra pension contribution that could bring you back below £100,000. To see your full salary breakdown first, use our UK Salary Calculator 2025/26.
UK £100k Tax Trap Calculator
Check how much of your Personal Allowance may be lost when your adjusted net income goes above £100,000. Estimate your income tax, National Insurance, take-home pay, and how much pension or salary sacrifice may bring you back below the tax trap.
Your Income
Enter your annual income before tax. Use yearly figures for the best estimate.
Quick Result
This summary shows your estimated position after your current and planned reductions.
| Adjusted net income | £0 |
|---|---|
| Personal Allowance left | £0 |
| Personal Allowance lost | £0 |
| Extra reduction needed to reach £100k | £0 |
Before vs After Extra Contribution
Compare your current position with the extra pension or salary sacrifice amount you entered.
| Result | Before extra | After extra |
|---|---|---|
| Adjusted net income | £0 | £0 |
| Personal Allowance | £0 | £0 |
| Income tax | £0 | £0 |
| National Insurance | £0 | £0 |
| Take-home pay | £0 | £0 |
Saving Breakdown
This shows how much tax and NI your extra contribution may save.
| Extra contribution tested | £0 |
|---|---|
| Estimated tax saved | £0 |
| Estimated NI saved | £0 |
| Net take-home reduction | £0 |
Important Notes
What Is the £100k Tax Trap?
The UK £100k tax trap occurs when your adjusted net income exceeds £100,000. At this point, the standard Personal Allowance of £12,570 begins to be withdrawn at a rate of £1 for every £2 earned above the threshold. By the time income reaches £125,140, the full Personal Allowance is gone.
This creates an effective marginal tax rate of around 60% on income between £100,000 and £125,140 — because you are paying 40% Higher Rate tax on each extra pound earned, while simultaneously losing 50p of tax-free allowance for every £1 earned, making that allowance taxable too.
The 60% Tax Trap — Worked Example
Here is how the trap works in practice:
| Scenario | Income | Personal Allowance | Effective Rate on Extra £1 |
|---|---|---|---|
| Below threshold | £99,000 | £12,570 (full) | 40% |
| In the trap | £110,000 | £7,570 (£5,000 lost) | ~60% |
| Above the trap | £130,000 | £0 (fully withdrawn) | 45% |
Someone earning £110,000 has £10,000 above the threshold. That reduces their Personal Allowance by £5,000. The tax cost: 40% on the £10,000 extra income (£4,000) plus 40% on the £5,000 of allowance now taxable (£2,000) = £6,000 extra tax on a £10,000 pay rise — an effective rate of 60%.
How to Use This £100k Tax Trap Calculator
Enter your annual salary and any bonus or commission. Then enter any current pension contribution, salary sacrifice, or Gift Aid that already reduces your adjusted net income. You can then enter an extra planned pension or salary sacrifice amount to compare your position before and after the additional contribution.
What Is Adjusted Net Income?
Adjusted net income starts with your total taxable income (salary, bonus, commissions, rental income, dividends) and subtracts pension contributions, salary sacrifice arrangements, and Gift Aid donations. It is adjusted net income — not gross salary — that determines whether and how much Personal Allowance you lose.
This is why pension contributions are such a powerful tool in this income range: a £10,000 pension contribution by someone earning £110,000 brings adjusted net income to £100,000, restores the full £12,570 Personal Allowance, and saves approximately £5,028 in tax.
Pension Contributions and the £100k Tax Trap
Pension contributions are the most commonly used tool for reducing adjusted net income. If your employer scheme supports salary sacrifice, the tax saving is even greater because salary sacrifice also reduces your National Insurance contributions.
Options to reduce adjusted net income include pension contributions, pension salary sacrifice, Gift Aid donations, and some allowable employment deductions. For a full salary and take-home view alongside your pension planning, use our UK Salary Calculator and our Mortgage Calculator to see how income changes affect your borrowing capacity.
Bonus Payments and the £100k Threshold
Bonuses frequently push people unexpectedly into the trap. Someone earning £95,000 base with a £10,000 bonus reaches £105,000 — losing £2,500 of Personal Allowance and paying significantly more tax than expected on that bonus. Enter your bonus amount separately in the calculator to see the full impact.
Frequently Asked Questions
What is the 60% tax trap exactly?
For every £2 earned above £100,000, you lose £1 of Personal Allowance. That lost allowance becomes taxable at 40%. Combined with 40% Higher Rate tax on the extra income itself, the effective rate on gross earnings between £100,000 and £125,140 is approximately 60% before National Insurance.
Does a pension contribution reduce adjusted net income?
Yes. Both personal pension contributions and pension salary sacrifice can reduce adjusted net income. This may restore some or all of your Personal Allowance if it brings you below the £100,000 threshold.
At what income does the Personal Allowance disappear completely?
The standard Personal Allowance of £12,570 is fully withdrawn at £125,140 of adjusted net income. Above this level you pay 45% Additional Rate tax on all income with no Personal Allowance.
Does this calculator work for Scotland?
This version is designed for England, Wales, and Northern Ireland. Scotland has different income tax bands. The Personal Allowance taper still applies to Scottish taxpayers, but income tax calculations will differ.
Is this an official HMRC calculator?
No. This is a free estimation tool for planning purposes only. For a precise tax calculation, use the official HMRC calculator or consult a qualified tax adviser or accountant.
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Important Disclaimer
This calculator is for general information and planning purposes only. It does not provide financial, tax, legal, pension, or professional advice. Tax rules can change, and your personal tax position depends on your tax code, pension type, employer scheme, student loan plan, residence, dividends, rental income, self-employment, and other individual circumstances. Always check with HMRC, your payroll team, a qualified accountant, or a regulated financial adviser before making important financial decisions.