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.
The calculator estimates your adjusted net income, Personal Allowance left, allowance lost, income tax, National Insurance, take-home pay, and the extra contribution that may bring you back below £100,000.
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 happens when your adjusted net income goes above £100,000. At this point, the standard Personal Allowance starts to reduce.
The Personal Allowance is the amount of income you can usually earn before paying income tax. For many people, the standard Personal Allowance is £12,570. But once your adjusted net income goes above £100,000, this allowance is reduced by £1 for every £2 of income above £100,000.
This means that by the time your adjusted net income reaches £125,140, the standard Personal Allowance is fully removed.
The reason this is called a “tax trap” is because you are not only paying higher-rate income tax on extra income, you are also losing part of your tax-free allowance at the same time. This can create a very high effective tax rate on income between £100,000 and £125,140.
How the £100k Tax Trap Works
Here is the basic idea:
If your adjusted net income is £100,000 or below, you usually keep your full standard Personal Allowance.
If your adjusted net income is above £100,000, your Personal Allowance starts reducing.
For every £2 above £100,000, you lose £1 of Personal Allowance.
If your adjusted net income reaches £125,140, the full standard Personal Allowance is removed.
For example, if your adjusted net income is £110,000, you are £10,000 over the £100,000 threshold. Your Personal Allowance may be reduced by £5,000. This means more of your income becomes taxable.
This is why people earning around £100,000 to £125,140 often look at pension contributions, salary sacrifice, or Gift Aid donations as ways to reduce adjusted net income.
What Is Adjusted Net Income?
Adjusted net income is not always the same as your gross salary.
Your adjusted net income usually starts with your total taxable income, then some deductions are taken into account. This may include certain pension contributions, salary sacrifice arrangements, and Gift Aid donations.
For this calculator, adjusted net income is estimated using:
Annual salary
Bonus or other taxable employment income
Minus current pension, salary sacrifice, or Gift Aid reductions
Minus any extra planned pension or salary sacrifice amount
This gives a practical estimate of where you stand against the £100,000 threshold.
Why Income Between £100,000 and £125,140 Can Be Expensive
The income range between £100,000 and £125,140 is expensive because of the Personal Allowance taper.
In simple terms, for every extra £2 you earn above £100,000, you may lose £1 of your tax-free allowance. That lost allowance then becomes taxable.
This can create an effective marginal tax rate that feels much higher than the normal higher-rate tax band. For many people in England, Wales, and Northern Ireland, this is often described as a 60% tax trap before considering National Insurance, student loans, childcare effects, or other deductions.
The exact effect depends on your income, tax position, pension contributions, salary sacrifice, and other personal circumstances.
How to Use This £100k Tax Trap Calculator
To use the calculator, enter your annual salary first. Then add any bonus, commission, or other taxable employment income.
Next, enter any current pension contribution, salary sacrifice, or Gift Aid amount that 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 extra contribution.
The calculator will estimate:
Adjusted net income
Personal Allowance left
Personal Allowance lost
Extra reduction needed to reach £100,000
Estimated income tax
Estimated employee National Insurance
Estimated annual take-home pay
Tax saved from extra pension or salary sacrifice
Before and after comparison
This makes it easier to see whether extra pension contributions or salary sacrifice could help you reduce the effect of the £100k tax trap.
Example: Earning £105,000
If someone earns £105,000 and has no pension or salary sacrifice deductions, they are £5,000 above the £100,000 threshold.
Because the Personal Allowance reduces by £1 for every £2 above £100,000, they may lose around £2,500 of Personal Allowance.
That means extra income is taxed directly, and part of the previously tax-free allowance becomes taxable too.
In this situation, putting more into a pension or using salary sacrifice may help reduce adjusted net income and recover some of the Personal Allowance.
Example: Earning £120,000
If someone earns £120,000, they are £20,000 above the £100,000 threshold.
That could reduce the Personal Allowance by around £10,000.
This can make the tax impact feel much heavier than expected. A person in this range may want to test how much pension contribution or salary sacrifice is needed to bring adjusted net income closer to £100,000.
The calculator can show the difference before and after an extra contribution, including estimated tax saved and the impact on take-home pay.
Pension Contributions and the £100k Tax Trap
Pension contributions are one of the common ways people try to reduce adjusted net income.
If pension contributions reduce your adjusted net income, they may help bring you back below the £100,000 threshold or reduce how much Personal Allowance you lose.
This is why many people earning between £100,000 and £125,140 compare:
Taking the full income as salary
Putting more into a pension
Using salary sacrifice
Reducing taxable income before the end of the tax year
This calculator does not tell you what to do. It simply gives an estimate so you can understand the numbers more clearly.
For a full view of your salary and estimated income, you can also use our Salary Calculator.
Salary Sacrifice and the £100k Tax Trap
Salary sacrifice can also affect adjusted net income if it reduces taxable salary. This may include pension salary sacrifice or other approved employer arrangements.
The benefit of salary sacrifice is that it may reduce taxable income and employee National Insurance, depending on the arrangement.
If you are close to the £100,000 threshold, even a small salary sacrifice amount could make a noticeable difference. For example, if your adjusted net income is £102,000, reducing it by £2,000 may help bring you back to £100,000 and preserve your full standard Personal Allowance.
Always check with your employer or payroll department before relying on salary sacrifice, because rules and employer schemes can vary.
Bonus Payments and the £100k Tax Trap
Bonuses can easily push someone into the £100k tax trap.
For example, someone with a salary of £98,000 may think they are below the threshold. But if they receive a £10,000 bonus, their total taxable employment income could rise to £108,000.
That may reduce their Personal Allowance and increase the tax impact of the bonus.
This calculator lets you enter salary and bonus separately so you can test different scenarios before or after a bonus payment.
Does the Calculator Include National Insurance?
Yes, the calculator estimates employee National Insurance as part of the take-home pay estimate.
National Insurance is separate from income tax. The calculator uses standard employee National Insurance assumptions for a simple annual estimate.
However, National Insurance can be affected by payroll timing, salary sacrifice setup, employment status, and other factors. Treat the result as a planning estimate, not a final payroll calculation.
Does This Calculator Work for Scotland?
This version is mainly designed for England, Wales, and Northern Ireland.
Scotland has different income tax bands and rates, so Scottish taxpayers may get a different result. The Personal Allowance taper still matters, but the income tax calculation can differ because Scottish income tax bands are separate.
If you pay Scottish income tax, use this calculator only as a rough guide and check your final position with a qualified tax adviser or official tax calculator.
Why the £100k Tax Trap Matters for Childcare
The £100,000 threshold can also matter for some childcare support rules.
For example, some UK childcare support can be affected when one parent earns above £100,000. This means the real impact of crossing the threshold may be bigger than income tax alone.
This calculator focuses on income tax, National Insurance, Personal Allowance, and adjusted net income. It does not calculate childcare entitlement or benefit loss.
If childcare support applies to you, treat this calculator as a starting point and check the official rules before making decisions.
What Counts as Income?
Income can include more than just your base salary.
Depending on your situation, income may include:
Salary
Bonus
Commission
Employment benefits
Rental income
Savings interest
Dividends
Self-employment profit
Pension income
Other taxable income
This calculator is mainly designed for employment income, salary, bonus, pension contribution, and salary sacrifice planning. If you have rental income, dividends, self-employment profits, or complex tax affairs, the result may not fully reflect your real tax position.
How to Reduce Adjusted Net Income
People commonly reduce adjusted net income through options such as:
Pension contributions
Salary sacrifice pension arrangements
Gift Aid donations
Some allowable employment deductions
The right option depends on your personal circumstances. Pension contributions may help with tax planning, but they also lock money away until pension access age. Salary sacrifice may reduce taxable salary, but it can also affect mortgage affordability, statutory pay calculations, or employer benefits in some cases.
Do not make major financial decisions based only on one calculator. Use this tool to understand the numbers, then check the details properly.
When Should You Use This Calculator?
This calculator is useful if:
You earn close to £100,000
You received a bonus
You are expecting a pay rise
You want to understand the Personal Allowance taper
You are considering extra pension contributions
You are considering salary sacrifice
You want to estimate your take-home pay
You want to know how much reduction may bring you back below £100,000
It is especially useful before the end of the tax year, when some people review pension contributions, bonuses, and salary sacrifice options.
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Frequently Asked Questions
What is the UK £100k tax trap?
The UK £100k tax trap is the point where your adjusted net income goes above £100,000 and your Personal Allowance starts to reduce. This can make income between £100,000 and £125,140 much more heavily taxed than people expect.
Why does the Personal Allowance reduce after £100,000?
The Personal Allowance is reduced by £1 for every £2 of adjusted net income above £100,000. This continues until the standard Personal Allowance is fully removed at £125,140.
What happens when income reaches £125,140?
At £125,140 of adjusted net income, the standard Personal Allowance is usually fully removed. This means there is no standard tax-free Personal Allowance left.
Is the £100k tax trap really a 60% tax rate?
It is often called a 60% effective tax trap because income in this band can be taxed at 40%, while the loss of Personal Allowance creates extra taxable income. National Insurance, student loans, childcare effects, and other factors may change the real impact.
Can pension contributions help with the £100k tax trap?
Pension contributions may help if they reduce your adjusted net income. If they bring your adjusted net income closer to or below £100,000, they may help preserve some or all of your Personal Allowance.
Can salary sacrifice help reduce adjusted net income?
Salary sacrifice may help if it reduces your taxable salary. Pension salary sacrifice is commonly used for this reason, but the exact effect depends on your employer scheme and personal circumstances.
Does a bonus count toward the £100,000 threshold?
Yes, taxable bonuses usually count toward your income. A bonus can push someone above £100,000 even if their base salary is below the threshold.
Is this calculator exact?
No. This calculator gives an estimate. It uses simplified assumptions and does not include every possible tax code, benefit, deduction, student loan plan, dividend, rental income, or personal circumstance.
Does this calculator include Scottish tax rates?
No. This version is mainly for England, Wales, and Northern Ireland. Scotland has different income tax bands and rates.
Should I increase my pension contribution to avoid the tax trap?
This depends on your personal financial situation. Extra pension contributions may reduce adjusted net income, but they also reduce accessible income now. Speak to a qualified financial adviser or tax professional if you are unsure.
Does Gift Aid reduce adjusted net income?
Gift Aid donations can affect adjusted net income in some situations. This calculator allows you to include reductions such as pension, salary sacrifice, or Gift Aid as a combined figure, but it does not provide a full tax return calculation.
Why is adjusted net income important?
Adjusted net income is used to decide whether your Personal Allowance is reduced. It can also affect some benefits, allowances, and thresholds.
Can this calculator help before the end of the tax year?
Yes. It can help you estimate whether you are likely to be above £100,000 and how much extra reduction may bring you closer to the threshold before the tax year ends.
Important Disclaimer
This calculator is for general information and planning only. It does not provide financial, tax, legal, pension, investment, or professional advice. Tax rules can change, and your personal tax position may depend on your tax code, pension type, employer scheme, benefits, student loan plan, childcare position, residence, dividends, savings interest, rental income, self-employment income, and other circumstances.
Always check your position with HMRC, your payroll department, a qualified accountant, or a regulated financial adviser before making important financial decisions.