Use this tax rebate calculator to check whether you have paid too much Income Tax through PAYE this tax year. Enter your total taxable pay and the tax taken off, from your P60, P45 or last payslip, and it compares that with the tax you should have paid on a standard tax code.
Your tax check
- Tax you should pay
- –
- Tax you paid
- –
- Estimated refund
- –
- Result
- –
In the example, someone who earned £18,000 and had £2,400 deducted should only have paid £1,086, so they may be owed about £1,314. That pattern is common after a period on emergency tax or when someone stops work part-way through the year.
How to use the tax rebate calculator
- Find your figures. Your P60 (end of year) or P45 (when you leave a job) shows “pay” and “tax” for the tax year. Add up all jobs since 6 April.
- Enter your taxable pay and the tax deducted.
- Add any work expenses you have not yet claimed, such as professional subscriptions or uniform washing.
- Choose where you live, because Scottish taxpayers use different bands.
Common reasons for overpaying tax
- Emergency tax code (such as 1257L W1 or M1, or 0T) after starting a new job without a P45.
- Leaving work part-way through the year, for example to study, travel or retire, so you did not use your full Personal Allowance.
- Two jobs where the wrong job got your allowance.
- Unclaimed work expenses, such as uniforms, tools, professional fees or business mileage in your own vehicle.
- Pension withdrawals, which are often taxed on an emergency basis the first time.
- Benefits in kind that ended but stayed in your tax code.
Emergency tax calculator: how emergency tax works
An emergency code such as 1257L M1 gives you one month’s Personal Allowance each payday, ignoring what you earned earlier in the year. If you started work in the autumn, you may have paid tax on income that should have been covered by your allowance. The GOV.UK guide to tax codes explains the codes. Use this calculator as an emergency tax calculator by entering your pay and tax so far.
Once your employer gets the right code, PAYE usually refunds the overpaid tax through your wages. If you have stopped working, you need to claim it back.
Tax rebate examples
| Taxable pay | Tax paid | Correct tax | Possible refund |
|---|---|---|---|
| £12,000 | £900 | £0 | £900 |
| £15,000 | £1,500 | £486 | £1,014 |
| £18,000 | £2,400 | £1,086 | £1,314 |
| £25,000 | £3,200 | £2,486 | £714 |
| £35,000 | £5,000 | £4,486 | £514 |
How to claim a tax refund
- If you are still working, ask HMRC to check your tax code. Overpaid tax normally comes back through your pay.
- If you have stopped work, claim through your HMRC online account or the HMRC app. See GOV.UK: claim a tax refund.
- For work expenses, claim online for the current year and up to four earlier years. See tax relief for employees.
- For earlier years, HMRC sends a P800 calculation after the tax year if your tax was wrong.
You do not need a refund company. They often charge 25% to 40% of the refund for something you can do yourself for free.
Related calculators
Check what your pay should look like with the monthly take home pay calculator, or work out tax on a one-off payment with the bonus tax calculator.
Frequently asked questions
How much tax rebate will I get?
The difference between the tax you paid and the tax due on your actual income. The tax rebate calculator estimates this for a standard tax code; HMRC confirms the exact amount.
How far back can I claim a tax refund?
Up to four tax years. In 2026/27 you can claim back to 2022/23.
How long does a tax refund take?
Online claims are often paid within a few weeks. Refunds through PAYE arrive with your next pay after the tax code is fixed.
Is the tax refund calculator accurate for Self Assessment?
It is designed for PAYE employees. If you complete a tax return, your refund or bill depends on all your income and payments on account.
About this calculator
This tax rebate calculator uses 2026/27 Income Tax bands, checked against GOV.UK on 9 November 2026. It assumes a full Personal Allowance and does not include benefits, savings or other income. Results are estimates; only HMRC can confirm a refund.