Tax Refund Calculator: Are You Owed Money Back? (2026/27)

Estimate your tax refund in seconds

Enter your gross pay, the tax you've actually had deducted, and any allowable expenses into the tax refund calculator above. It compares what you paid against what you should have paid under the 2026/27 rules, and shows the likely difference. Treat the result as a guide for whether it's worth contacting HMRC, not as a guaranteed payout.

Why people overpay tax in the first place

Most overpayments happen because PAYE is a blunt instrument. Your employer deducts tax based on the code HMRC gives them, and that code is only as accurate as the information HMRC holds. When something changes mid-year, the deductions often lag behind reality. Seeing too much tax come off your pay is frustrating, but in a lot of cases it's genuinely reclaimable.

The most common reasons you end up owed a tax refund are:

• Emergency tax on a new job. Start a job without a P45 and you're often put on an emergency or month-1 code, which ignores the pay and tax already used up earlier in the year.
• The wrong tax code. A code that doesn't reflect your full Personal Allowance (£12,570 for 2026/27) means you lose tax-free pay you were entitled to.
• Stopping work part-way through the year. If you stop working in, say, August, you've only used part of your annual allowance, so the tax taken while you were working may be too high.
• Job expenses you never claimed. Uniform laundering, professional subscriptions, tools, and business mileage in your own car can all reduce the tax you owe.
• Two jobs or a job plus a pension. The Personal Allowance can end up applied to the wrong source, or not split sensibly, leaving you overtaxed on one of them.

How the tax refund calculator works

A PAYE refund estimate comes down to one comparison: the tax you should have paid on your real income, against the tax that was actually deducted. Put simply:

Refund (estimate) = Tax actually deducted − Tax correctly due on your income

To find the tax correctly due, the calculator rebuilds your bill from scratch using the 2026/27 figures. Everyone starts with a Personal Allowance of £12,570 - the slice you can earn before any income tax applies. Income above that is taxed in bands:

• 20% basic rate on the first £37,700 of taxable income (income after the allowance)
• 40% higher rate on taxable income from £37,700 up to £125,140
• 45% additional rate on taxable income above £125,140

So the working order is: take your gross income, subtract your Personal Allowance to get taxable income, apply the band rates above, and that's the tax you genuinely owe. Subtract any allowable expenses from your income before you tax it, because expenses reduce the taxable figure rather than the tax directly. The gap between that correct figure and what landed on your payslips is your potential refund.

One important regional note: if you live in Scotland, your income tax is set by the Scottish Government and uses different rates and bands (starter, basic, intermediate, higher, advanced and top rates), although the £12,570 Personal Allowance is the same UK-wide. A refund worked out on rest-of-UK bands won't be accurate for a Scottish taxpayer, so use a Scotland-specific figure if that's you. National Insurance, by contrast, is calculated per pay period and is rarely refundable in the same way, so a true overpayment refund almost always relates to income tax.

Worked example: emergency tax on a new starter

Take Priya, a graphic designer who left one job in May 2026 and started a new role in July without handing over her P45. Her new employer puts her on an emergency code, taxing her as if July is the first month of the year and ignoring the two months she was out of work.

Over the 2026/27 year she earns £30,000 gross from the new job. Because of the emergency code, more tax came off in the early months than her real position justified. Let's check what she should owe:

• Gross income: £30,000
• Less Personal Allowance: £30,000 − £12,570 = £17,430 taxable
• All of it sits in the basic-rate band, taxed at 20%: £17,430 × 0.20 = £3,486

If the emergency code caused £4,000 to be deducted across the year, Priya's estimated refund is £4,000 − £3,486 = £514. In practice HMRC usually corrects an emergency code automatically once it receives full pay details, and any overpayment is repaid - but it's worth checking rather than assuming it sorts itself out.

Worked example: a nurse claiming uniform and mileage expenses

Now take Daniel, a nurse on £30,000 who washes his own uniform and occasionally drives between sites in his own car. He's already paid the right tax on his salary - £3,486 as above - but he's never claimed his allowable expenses.

Say his allowable expenses come to £500 over the year (a flat-rate uniform allowance plus some business mileage at HMRC's approved rate of 45p per mile for the first 10,000 miles). Expenses reduce taxable income, so:

• Adjusted taxable income: £17,430 − £500 = £16,930
• Tax now due: £16,930 × 0.20 = £3,386
• Refund: £3,486 − £3,386 = £100

It's a modest sum in one year, but you can usually backdate expense claims for up to four tax years, so a long-standing claim can be worth several hundred pounds. As a basic-rate taxpayer, the refund is simply 20% of the expenses you claim; a higher-rate taxpayer gets 40% relief on the same expenses.

2026/27 income tax rates & thresholds (England, Wales & NI)

These are the figures the calculator uses to rebuild your correct bill. They apply to England, Wales and Northern Ireland; Scotland has its own bands.

Source: gov.uk income tax rates, checked for the 2026/27 tax year. Note the Personal Allowance is reduced by £1 for every £2 you earn over £100,000 and disappears entirely at £125,140 - high earners who hit this taper sometimes find they've actually underpaid rather than overpaid.

How to claim a tax refund from HMRC

Once the calculator suggests you might be owed money, the claim route depends on why. The good news is that claiming directly is free - you never have to pay a percentage to anyone.

• Wrong tax code or emergency tax: contact HMRC, or check and update your code in your personal tax account. Once corrected, an in-year overpayment is usually repaid through your next payslip or sent directly after the tax year ends, often via a P800 calculation.
• Job expenses: claim online through gov.uk if your expenses are under the annual limit, or include them on a Self Assessment return if you already file one. You can backdate up to four tax years.
• Left the UK or stopped working mid-year: use the relevant HMRC form (for example, the P50 if you've stopped working) to claim the part-year overpayment before the year ends.

You can start most claims at gov.uk's claim a tax refund service. If HMRC owes you money after the tax year, it often sends a P800 tax calculation automatically, and you can request the refund online or wait for a cheque.

How long does a tax refund take?

Timing varies by claim type. An online refund through your personal tax account or a P800 can land in your bank within about five working days of you requesting it; a cheque takes longer, often a few weeks. Expense claims and Self Assessment refunds can take several weeks to process, especially around the January and April peaks. If you're still waiting well beyond that, it's worth chasing HMRC directly.

Common mistakes and things to watch

• Paying a rebate firm a big cut. Plenty of companies advertise “get your tax back” and then take 30%–40% plus VAT of your refund. You can claim everything yourself for free directly from HMRC. Always read the small print before signing a deed of assignment, which can hand future refunds to the firm too.
• Assuming a refund means you definitely overpaid. The calculator is an estimate. If HMRC's records show extra income - a second job, savings interest, a benefit in kind on a P11D - your real position may differ.
• Forgetting the Scotland difference. Scottish taxpayers have different bands, so a rest-of-UK estimate can be off. Check using Scottish rates if you live there.
• Missing the four-year window. You can only reclaim overpaid tax for the previous four tax years. Older overpayments are generally lost, so don't sit on a claim.
• Confusing a refund with a reduced future code. Sometimes HMRC corrects an overpayment by adjusting your tax code going forward rather than paying cash, so you see slightly higher take-home pay instead of a lump sum.

If your situation is more complex - multiple income sources, a high-earner allowance taper, or self-employment alongside a job - it's worth modelling your full position. Our income tax calculator rebuilds your whole bill from gross pay, and the emergency tax calculator shows exactly how much an emergency code costs you in a given month.

This tax refund calculator gives estimates for guidance only and isn't personal tax or financial advice; check your own figures with HMRC or a qualified adviser before acting.

Related calculators

To dig deeper into a possible refund, try the tax code calculator to confirm your code is right, the mileage allowance calculator to value business journeys in your own car, and the marriage allowance calculator if you or your partner could transfer part of your Personal Allowance.

Related tools

• Work expense tax rebate calculator, claim uniform and tools relief for free.
• HMRC letter decoder, understand a refund letter.