How HMRC knows you are owed money and what happens next

HMRC (Her Majesty's Revenue and Customs) will contact you if their records show you have paid too much tax. You do not need to chase them — they will write to you with a calculation and instructions. The letter will come to the address they have on file, usually within a few weeks of the tax year ending on 5 April.

If you have moved house or changed your name since you last dealt with HMRC, update your details before the tax year ends. You can do this through your personal tax account online, or by calling HMRC directly. If HMRC cannot reach you, they will hold the money and you will have to claim it yourself.

The refund itself takes time. HMRC processes claims in batches, and a cheque or bank transfer typically arrives four to six weeks after they receive your claim. If you have given them your bank details, the money goes directly into your account — this is faster and safer than waiting for a cheque.

Key Takeaways

  • HMRC will write to you if they owe you money, but only if they have your correct address on file.
  • You can check whether HMRC owes you a refund by logging into your personal tax account online or calling 0300 200 3300.
  • If you have moved or changed your name, update your details with HMRC before the tax year ends to avoid delays.
  • Refunds take four to six weeks to arrive once HMRC processes your claim, faster if you provide your bank details.
  • Keep any letters from HMRC and payslips or P60 forms that show how much tax you paid, in case HMRC asks for proof.

Checking your personal tax account online

The fastest way to see whether HMRC owes you money is through your personal tax account. You will need a Government Gateway user ID and password — if you do not have one, you can create it on the GOV.UK website in a few minutes using your National Insurance number and a recent payslip or tax return.

Once you are logged in, look for the section marked "Tax year overview" or "Payments". This will show you how much tax you paid during the year and how much you should have paid. If the numbers do not match, the difference is what HMRC owes you. The account also shows the status of any refund you have already claimed — whether it is being processed, approved, or on its way to your bank.

If you cannot access your account online, or if the information does not look right, you can call HMRC on 0300 200 3300. Have your National Insurance number ready. The phone lines are busiest in April and May, so calling in June or later will usually get you through faster.

What documents you need to claim a refund

HMRC usually has all the information they need already — they have records from your employer or pension provider showing how much tax was taken from your pay. You do not need to send documents unless HMRC asks for them. However, it is worth keeping copies of anything that shows how much tax you paid, in case they request proof.

The most useful documents are your P60 (the form your employer gives you at the end of the tax year showing your total pay and tax), your payslips, or your Self Assessment tax return if you filed one. If you are claiming a refund because you worked part-time or had two jobs, keep payslips from both employers. If you are claiming because you were unemployed for part of the year, a letter from Jobcentre Plus or your benefits provider can help explain the gap in your income.

Store these documents for at least six years. HMRC can ask for proof of income or tax paid at any point during that time, and having the paperwork ready means your claim will not be delayed.

Claiming a refund if HMRC has not contacted you

If you know you have overpaid tax but HMRC has not written to you, you can claim the refund yourself. This usually happens when you have moved house and HMRC's letter went to your old address, or when you worked for multiple employers and the tax system did not catch the overpayment automatically.

The easiest route is through your personal tax account. Log in, find the section for "Refunds" or "Overpayments", and follow the steps to submit a claim. You will need to explain why you think you have overpaid — for example, "I worked part-time from January to March and paid emergency tax" or "I had two jobs and one employer did not know about the other". HMRC will check your records and either approve the claim or ask for more information.

If you do not have an online account, you can write to HMRC at the address on any letter they have sent you, or call 0300 200 3300 and ask them to send you a claim form. The form is straightforward — it asks for your name, National Insurance number, the tax year you are claiming for, and how much you think you have overpaid. Send it with copies of your payslips or P60 if you have them.

Refunds for Self Assessment taxpayers

If you file a Self Assessment tax return, HMRC will calculate any refund owed to you once they have processed your return. You do not need to claim separately — the refund appears in your tax account a few weeks after you submit the return, and HMRC will send it to your bank or by cheque.

Self Assessment returns are due by 31 January following the end of the tax year. If you file online, HMRC processes the return faster and you will see the refund status in your account sooner. If you file on paper, processing takes longer — usually eight to ten weeks.

If you have registered for Self Assessment but do not need to file a return (for example, because your income is below the threshold), you can still claim a refund for overpaid tax. Contact HMRC on 0300 200 3300 and explain your situation. They will tell you whether you need to file a return or whether they can process a refund claim without one.

What to do if your refund does not arrive

If HMRC approved your refund but the money has not arrived after six weeks, check your personal tax account first to see the current status. The account will tell you whether the refund is still being processed, whether it has been sent, or whether there is a problem.

If the account says the refund was sent but you have not received it, contact HMRC on 0300 200 3300. If you provided your bank details, ask them to check whether the payment was sent to the correct account — sometimes a typo in the account number means the money goes to the wrong bank. If the refund was sent as a cheque, ask HMRC to cancel it and send a replacement or arrange a bank transfer instead.

If HMRC rejected your claim or asked for more information, they will have written to you explaining why. Read the letter carefully and follow the instructions. If you do not understand what they are asking for, call them on the number in the letter — they can usually explain over the phone and tell you exactly what documents to send.

Refunds if you have moved abroad or changed your circumstances

If you have moved outside the UK, HMRC can still send you a refund, but the process takes longer. You will need to provide proof of your new address and confirm your tax residency status. Contact HMRC on 0300 200 3300 and tell them you have moved abroad — they will send you a claim form and explain what documents you need to send.

If your circumstances have changed since you paid the tax — for example, you were made redundant, you retired, or you became self-employed — this does not stop you claiming a refund for overpaid tax. The refund is based on what you actually earned and paid during that tax year, not on your current situation. Tell HMRC about the change when you claim, as it may affect how much you owe or are owed in future years.

Frequently Asked Questions

How long does it take HMRC to process a refund claim?

Once HMRC receives your claim, processing usually takes four to six weeks. If you provide your bank details, the refund goes directly into your account. If you ask for a cheque, it takes slightly longer because HMRC has to print and post it. During busy periods like April and May, processing can take longer.

Can I claim a refund for tax paid more than one year ago?

Yes. HMRC can refund overpaid tax going back several years if you did not claim at the time. However, the longer ago the overpayment was, the more evidence you may need to provide. Keep payslips, P60 forms, or tax returns from previous years if you think you have overpaid.

What if I think HMRC has calculated my refund wrong?

Contact HMRC on 0300 200 3300 and explain what you think is incorrect. Have your payslips or P60 ready so you can walk through the calculation together. If you disagree with their decision, you can ask for a formal review, though this takes longer.

Do I have to accept a refund as a cheque, or can I ask for it to go to my bank account?

You can ask for the refund to go to your bank account instead of a cheque. Tell HMRC your sort code and account number when you claim, or update your details in your personal tax account. Bank transfers are faster and safer than cheques.

What if I owe HMRC money from a previous year — will they take it from my refund?

Yes. If you owe tax from an earlier year, HMRC will use your refund to pay off the debt first. They will write to you explaining this before they process the refund. If you think the debt is wrong, contact HMRC to dispute it before claiming your refund.