How to Claim a Tax Refund from HMRC in 2026

Every year, millions of UK taxpayers overpay their tax without realising it. HMRC themselves estimate that around 3-4 million people are owed a refund in any given year. If you have been on the wrong tax code, changed jobs, or only worked part of the year, there is a good chance you have overpaid. This guide walks you through exactly how to check and claim your money back.

Who Can Claim a Tax Refund?

You may be entitled to a tax refund if any of the following apply to you:

• You were put on an emergency tax code when starting a new job
• You had multiple jobs and your tax-free Personal Allowance was not split correctly
• You stopped working part way through the tax year
• You paid tax on a pension lump sum
• You had work expenses that you were not claiming relief for
• Your tax code was simply wrong for any reason

The key thing to understand is that HMRC operates PAYE (Pay As You Earn) on an estimated basis. Your employer deducts tax based on the assumption you will earn the same amount every pay period for the entire year. When that assumption is wrong, you overpay.

Step 1: Check If You Are Owed a Refund

Before contacting HMRC, you need to know whether you have actually overpaid. The quickest way to check is to use a free tool like AuditMyTax, which lets you upload your P60 or payslip and instantly see whether the tax deducted matches what you should have paid based on your actual earnings.

Alternatively, you can check manually by logging into your HMRC Personal Tax Account at gov.uk. Look for a P800 tax calculation, which HMRC typically sends out between June and October after the end of each tax year.

Step 2: Gather Your Documents

To make a claim, you will need:

• **P60** - Your end-of-year certificate from your employer showing total pay and tax deducted
• **P45** - If you left a job during the year
• **Payslips** - Useful for verifying monthly deductions
• **Your National Insurance number**

Keep these documents safe. Your P60 is especially important as it is the definitive record of what you earned and what tax was deducted in a given tax year.

Step 3: Claim Your Refund

There are several ways to claim:

**Online via your Personal Tax Account:** Log in at gov.uk/personal-tax-account. If HMRC has already identified an overpayment via a P800, you can claim it directly. Refunds requested online are usually paid within 5 working days.

**By phone:** Call HMRC on 0300 200 3300 (Monday to Friday, 8am to 6pm). Have your National Insurance number, P60, and details of income and tax paid ready. Ask them to review your tax for the year in question.

**By post:** Write to HMRC at Pay As You Earn and Self Assessment, HM Revenue and Customs, BX9 1AS. Include your full name, address, NI number, the tax year you are querying, and details of why you believe you have overpaid. Tools like AuditMyTax can generate a formal reconciliation letter for you, which makes this process much simpler.

How Far Back Can You Claim?

You can claim a tax refund for the current tax year plus the previous 4 tax years. In 2026, that means you can go back as far as the 2021/22 tax year. Do not leave it too late because once a tax year falls outside the 4-year window, that money is gone for good.

How Much Could You Get Back?

The amount varies hugely depending on your circumstances. Someone on an emergency tax code for a few months might be owed a few hundred pounds. Someone who had two jobs with incorrectly split allowances could be owed over a thousand. The average PAYE refund is around 750 pounds, but it is not uncommon to see claims of 1,500 pounds or more for multiple years.

Common Mistakes to Avoid

• **Waiting for HMRC to contact you.** While HMRC does send P800s, they do not always catch every overpayment. It is always worth checking yourself.
• **Throwing away your P60 or P45.** These documents are essential evidence. If you have lost them, ask your employer for a copy.
• **Ignoring emergency tax codes.** If your payslip shows tax code 0T, 1257L M1, or 1257L W1, you are likely overpaying. Get it sorted immediately by contacting HMRC or your employer.
• **Paying a claims company a percentage.** You do not need to pay anyone a cut of your refund. You can claim directly from HMRC for free, or use a tool like AuditMyTax that charges a small flat fee rather than taking a percentage.

Final Thoughts

Checking whether you are owed a tax refund takes just a few minutes and could put hundreds or even thousands of pounds back in your pocket. Start by checking your P60 against what you should have paid, and if the numbers do not match, contact HMRC. The process is straightforward and entirely free.