Could HMRC Owe You Money? How to Check for a Tax Refund

Millions of PAYE employees overpay tax every year without realising it — usually because of an incorrect tax code, an emergency code applied when starting a new job, or unclaimed work expenses. Checking takes about ten minutes and costs nothing.

Why overpayments happen

Your tax code tells your employer how much tax-free income you get before deductions start. Codes go wrong for common reasons: starting a new job partway through the tax year, having more than one employer, receiving a company benefit that's since stopped, or moving in and out of work. GOV.UK's guidance on repayments covers the main categories HMRC deals with, from PAYE overpayments to Self Assessment refunds.

What you might be able to claim

Beyond a wrong tax code, common refund triggers include: uniform or tool costs for your job that your employer didn't reimburse, professional subscription fees required for your role, mileage for business travel using your own car, or working from home costs during periods your employer required it. Each has its own eligibility rules, so it's worth checking the specific criteria on GOV.UK rather than assuming you qualify.

How HMRC will contact you (and how scammers won't)

HMRC does not tell you about a tax refund by text message or email link asking you to "click here to claim." This is one of the most common scam formats in the UK. If you get a message like this, don't click through — go directly to gov.uk or log into your Personal Tax Account yourself.

Checklist: how to check for a refund

1. Log into your Personal Tax Account on GOV.UK using your Government Gateway ID — this shows your current tax code and recent PAYE history
2. Check your tax code against the HMRC tax code checker — common wrong codes include emergency codes (like 1257L W1/M1) applied after a job change
3. Gather P60s or P45s for the years you want to check — HMRC allows claims going back four tax years
4. Check for job expenses you paid yourself and weren't reimbursed for — uniforms, tools, professional fees, or business mileage
5. If self-employed, check your Self Assessment statement for any overpaid balance showing as a credit
6. Submit a claim online through your Personal Tax Account, or by post using the relevant HMRC form if you're not registered online
7. Be wary of "tax refund" text messages or emails — go direct to GOV.UK rather than clicking links, per HMRC's own scam warnings
8. Track your claim — refunds are typically processed within a few weeks once submitted correctly

International comparison

In the US, the equivalent process runs through the IRS, where over-withholding is reconciled automatically when you file your annual tax return — there's no separate refund claim process for most employees, since the return itself calculates the balance. In Australia, the Australian Taxation Office similarly settles over- or under-payment through the annual tax return via myGov, rather than requiring a standalone claim for most PAYG employees. The UK's PAYE system, by contrast, can leave money unclaimed indefinitely if you don't proactively check, because most employees never file an annual return at all.

Key Numbers

• 4 years — how far back you can claim a UK tax refund
• £1,000+ — not unusual for uniform, mileage or subscription claims accumulated over several years, though amounts vary widely by circumstance
• 10 minutes — roughly how long it takes to check your tax code online

Sources

• GOV.UK: Repayments and refunds from HMRC — detailed information
• GOV.UK: Personal Tax Account
• GOV.UK: Check your Income Tax for the current year
• ICAEW: Tax news in brief, 1 July 2026

Educational content only — not financial advice.