Overpaid Tax Refund - How to Check If HMRC Owes You Money

Published 7 August 2026 · Facts checked against the sources listed at the end · Guidance, not financial advice

Paying the correct amount of tax is an important part of managing your finances. However, mistakes can happen, and thousands of people across the UK pay more tax than they actually owe each year.

An overpaid tax refund can occur for several reasons, including changes in employment, incorrect tax codes, multiple jobs, or periods of unemployment. If you've paid too much tax, HM Revenue & Customs (HMRC) may owe you money.

The good news is that many tax overpayments are refundable. Knowing how to check your tax records, understand HMRC letters, and claim any money you're owed can help you avoid missing out.

In this guide, we'll explain what an overpaid tax refund is, why it happens, how to check if you're due a refund, and what steps you can take to reclaim your money.

What Is an Overpaid Tax Refund?

An overpaid tax refund is money returned to you after HMRC determines that you've paid more Income Tax than you were legally required to pay. Most people can go back four tax years — so in 2026/27 you can still reclaim overpayments from 2022/23 onwards.

Common Causes of Overpaid Tax

• A wrong tax code — the single biggest cause. Check the code on your payslip; 1257L is standard for most people with one job. Our Money Map estimates a wrong code costs around £500 a year.
• Starting or leaving a job mid-year, or being put on an emergency code (ending W1/M1 or X).
• Having more than one job or pension, with allowances applied in the wrong place.
• Stopping work part-way through the year — redundancy, retirement, career breaks.
• Not claiming reliefs you're entitled to — Marriage Allowance (worth £252 a year), uniform and professional-fee flat rates, or working-from-home relief where you qualify.

How to Check If HMRC Owes You Money

1. Sign in to your Personal Tax Account (free) and open "Pay As You Earn". It shows what HMRC thinks you earned and paid each year.
2. Watch for a P800 letter or Simple Assessment after the tax year ends — it tells you if you overpaid or underpaid. We have a full guide: what a P800 means and what to do.
3. If the P800 says you're owed money, claim it straight into your bank via your tax account or the HMRC app — usually paid within 5 working days. If you do nothing, HMRC eventually sends a cheque.

Beware Refund Scams

HMRC never texts or emails "click here for your refund" links. If a message pushes you to enter bank details, check it with our scam checker before you touch it.