How to claim a tax refund from HMRC

Common reasons people are owed a refund

Overpaid tax happens more often than people expect, usually without any mistake on the taxpayer's part. The most common causes are: being on an emergency or otherwise incorrect tax code for part of the year, stopping work partway through the tax year without using your full Personal Allowance, having too much tax deducted on a redundancy payment, claiming expenses or reliefs you were entitled to but never actually claimed, or simply having a tax code that didn't catch up with a change in your circumstances quickly enough.

Work expenses are another commonly missed one — uniform laundering, professional subscriptions, or using your own vehicle for work travel beyond a normal commute can sometimes be claimed back, either through a simple online form for smaller amounts or via Self Assessment for larger or more complex claims.

How HMRC tells you a refund is due

If HMRC's own systems spot an overpayment at the end of the tax year, they usually send a P800 tax calculation letter or an equivalent digital message explaining the figures and how the refund will be paid. Not every overpayment is caught automatically, though — if you think you're owed money and haven't heard from HMRC, you can check and claim directly through your Personal Tax Account on gov.uk.

A worked example: leaving a job partway through the year

Imagine someone earning £3,000 a month who leaves their job at the end of August, five months into the tax year, and doesn't work again for the rest of that tax year. Through cumulative PAYE, their tax to date after 5 months would be worked out against 5/12 of the annual Personal Allowance (£5,237.50), on £15,000 of pay — giving taxable pay of £9,762.50 and tax paid of roughly £1,952.50 over those 5 months. But their actual income for the whole tax year, since they never work again, is just £15,000. Against the full £12,570 annual allowance, their real taxable income for the year is only £2,430, meaning their real tax bill for the year is just £486 — leaving a refund of roughly £1,466.50 due once the tax year ends or their new circumstances are reported.

How refunds are actually paid

How long it takes and what to watch for

Refunds through PAYE correction or Self Assessment are generally processed within a few weeks once HMRC has everything it needs, though it can take longer during busy periods. One important warning: HMRC never asks for a refund to be claimed by clicking a link in a text message or email, or asks for card or bank details that way — refund scams that mimic HMRC branding are extremely common, and genuine refunds are claimed through your official Personal Tax Account or by HMRC contacting you directly through the post.

Common mistakes

• Assuming no letter means no refund is due — not every overpayment is automatically detected; it's worth checking yourself, especially after leaving a job partway through a tax year.
• Clicking links in unsolicited texts or emails claiming to be from HMRC about a refund — always go directly to gov.uk rather than following a link, since this is one of the most common tax-related scams.
• Forgetting that a refund claim generally has a time limit — most refund claims need to be made within four years of the end of the relevant tax year.
• Assuming redundancy pay is always taxed correctly at the time — large one-off payments can sometimes be taxed more heavily than necessary in the month they're paid, which may be reclaimable afterwards.
• Not updating your details with HMRC after a life change — an out-of-date address or bank account can delay a refund that's already been approved.