How to Check if HMRC Owes You a Tax Refund (2026)

Every year a large number of UK employees pay more Income Tax through PAYE than they actually owe — often without ever realising it. HMRC reconciles most accounts automatically after the tax year ends and issues a P800 calculation, but the system is not perfect. If your circumstances changed mid-year, if you had more than one job, or if you were entitled to a relief you never claimed, the money can sit unrefunded until you ask for it.

This guide walks through the seven most common reasons you may be owed money, how to check each one for free, and how to make the claim yourself so you keep 100% of the refund.

First, the two-minute free checks

Before anything else, do these two quick checks. Together they catch the majority of overpayments.

• —Check your tax code. The standard code for 2025/26 is 1257L. If yours is BR, D0, D1, 0T, or has a W1, M1 or X on the end, you may be on emergency tax and overpaying right now.
• —Open your Personal Tax Account on GOV.UK. It shows your current tax code, your estimated income, and any P800 refund HMRC has already calculated but not yet paid.

The 7 most common reasons HMRC owes you money

1. Emergency tax after starting a new job. If you started work without a P45, your employer may have used an emergency code, taxing you as though you earn the same every month with no backdated allowance. This is the number-one cause of overpayment.

2. You changed jobs or had two jobs at once. Overlapping employments frequently lead to your tax-free Personal Allowance being applied incorrectly, so tax is taken twice.

3. You stopped working part-way through the year. If you left a job and did not work for the rest of the tax year, you likely did not use your full Personal Allowance — the unused portion is refundable.

4. Work-from-home tax relief you never claimed. If your employer required you to work from home, you can claim tax relief worth £6 per week of additional household costs without keeping receipts.

5. Marriage Allowance. If you are married or in a civil partnership and one of you earns under the Personal Allowance, the lower earner can transfer £1,260 of allowance to the other — worth up to £252 a year, and backdatable.

6. Uniform, tools or professional fees. If you pay to launder a required uniform, buy your own tools, or pay professional body membership (for example a nursing or accountancy body), you can claim tax relief via form P87.

7. Overpaid tax on a pension lump sum. Taking money flexibly from a pension often triggers an emergency tax code and a large over-deduction, reclaimable with forms P55, P53Z or P50Z.

How to claim your refund (for free)

Which route you use depends on why you overpaid:

• —P800 says you are owed money: you can usually claim it online through your Personal Tax Account, and it is paid within about five working days, or by cheque within a few weeks.
• —Work-related expenses (uniform, tools, professional fees, working from home): claim with form P87 online.
• —Marriage Allowance: apply on GOV.UK; HMRC adjusts both tax codes and refunds any backdated amount.
• —Pension lump-sum overpayment: use P55, P53Z or P50Z depending on your situation.
• —Left the UK or stopped working: form P50 or P85.

How far back can you claim?

You can reclaim overpaid PAYE tax for the four previous tax years. That means claims stack up: if you have never checked, you may be owed money across several years at once. There is a strict deadline for each year, so the sooner you check, the more you can recover.

A quick note on scam awareness: HMRC never texts or emails you a link to "claim your refund". Always start from GOV.UK directly, and never pay a percentage-based reclaim firm for something you can do yourself in minutes.