Overpaying tax is more common than most people realise. It happens when you have the wrong tax code, leave a job mid-year, claim allowable expenses you did not deduct at source, or receive a taxable benefit that was wrongly calculated. The money belongs to you — HMRC will repay it, but you usually need to claim it.
Common Reasons for Overpaying Tax
The most frequent causes of overpaid income tax in the UK include: being put on an emergency tax code when starting a new job; leaving employment partway through the tax year without using your full personal allowance; having multiple jobs where your personal allowance is allocated incorrectly; overpayment on pension withdrawals (particularly first-time flexible access); and not claiming all allowable work expenses. In all of these situations, you may be owed a refund.
How to Claim a Tax Refund If You Are Employed (PAYE)
If you are employed and pay tax through PAYE, HMRC may automatically calculate and issue a refund at the end of the tax year via a P800 letter. If you receive a P800 showing you have overpaid, you can claim online within 45 days and receive your refund within 5 working days. If you have not received a P800 but believe you have overpaid, you can claim directly through your Personal Tax Account at gov.uk/personal-tax-account.
How Far Back Can You Claim?
Our Verdict
Claiming a tax refund from HMRC is straightforward and free. If you have overpaid in the last 4 years, start with your Personal Tax Account at gov.uk. The process takes minutes for most employed taxpayers and refunds arrive within days. Never pay a third party to do something you can do yourself for free.
Frequently Asked Questions
How do I claim a tax refund from HMRC?
Log into your Personal Tax Account at gov.uk/personal-tax-account. If HMRC has issued a P800 letter, follow the link in it. Self-employed taxpayers claim via their Self Assessment return.
How long does a tax refund take UK?
Once HMRC approves your claim, refunds are typically paid within 5 working days to your bank account, or up to 5 weeks by cheque if no bank details are held.
How far back can I claim a tax refund?
You can claim back overpaid tax for the last 4 complete tax years. Claims must be made before 5 April in the 4th year following the tax year in question.
Last updated: April 2026 · Author: Chandraketu Tripathi