Key takeaways
- A Self Assessment refund is due when your return shows you paid more tax than you owe, often because payments on account exceeded the final bill.
- If you asked for a refund on your return HMRC usually pays it automatically; otherwise choose 'Request a Repayment' in your Self Assessment online account.
- GOV.UK says refunds usually arrive within 2 weeks, with security checks adding up to 12 more weeks.
- HMRC may not repay an overpayment if you have tax due in the next 45 days, and deducts it from that tax instead.
- You can apply to reduce payments on account by 31 January after the end of the tax year, but interest applies if you reduce them too far.
You get a Self Assessment tax refund when your tax return shows you have paid more tax than you owe, most often because your payments on account were higher than your final bill. If you asked for the refund on your return, HMRC usually pays it automatically; if not, sign in to your HMRC online account and choose 'Request a Repayment' in your Self Assessment account, or 'Claim a tax refund' in your personal tax account.
This guide covers refunds on Self Assessment returns, including returns for the 2025/26 tax year (6 April 2025 to 5 April 2026) that are due by 31 January 2027. The rules and timescales below were checked against GOV.UK on 17 September 2026.
When you might be owed tax back through Self Assessment
If you are registered for Self Assessment, HMRC adjusts your bill automatically when you have overpaid or underpaid, and you will not get a P800 tax calculation letter (GOV.UK). Your return is where any overpayment shows up. Common reasons include:
- Payments on account higher than your final bill. Payments on account are based on last year's tax. If you earn less than estimated, you may be able to claim a refund.
- Construction Industry Scheme (CIS) deductions. Deductions a contractor takes are advance payments towards your tax. HMRC takes them off what you owe and pays back any refund due (GOV.UK).
- Higher rate relief on pension contributions. If you pay Income Tax above 20% and your pension provider claims the first 20% for you, you claim the extra relief on your return (GOV.UK).
- Tax already taken at source. Tax deducted from a job, pension or other income counts towards your bill, so it can cover more than you owe.
- A mistake on an earlier return. Correcting it can reduce your tax. See how to amend a Self Assessment tax return.
How payments on account lead to a refund
Payments on account are two advance payments towards your next bill, each normally half of last year's tax, due by 31 January and 31 July. You must make them unless last year's bill was less than £1,000 or more than 80% of your tax was paid at source (GOV.UK). If your income falls, the two payments can add up to more than the final bill for the year.
Here is an illustration. Your 2024/25 tax was £6,000, so you paid two payments on account of £3,000 for 2025/26, on 31 January 2026 and 31 July 2026. Your profit dropped and your 2025/26 return shows tax of £4,000. The example assumes less than 80% of your tax is paid at source.
| Amount | |
|---|---|
| Payments on account made for 2025/26 | £6,000 |
| Tax due for 2025/26 | £4,000 |
| Overpaid for 2025/26 | £2,000 |
| First payment on account for 2026/27, due 31 January 2027 (half of £4,000) | £2,000 |
Because a £2,000 payment on account falls due on 31 January 2027, whether you see cash back depends on timing. HMRC may not pay a refund if you have tax due in the next 45 days; instead the money is deducted from the tax you owe (GOV.UK). Claim the refund within 45 days of that payment and HMRC may use the overpayment to cover it instead. File earlier and you can claim the £2,000 back, but the £2,000 payment on account is still due on 31 January 2027. Our payments on account guide explains how the amounts are set.
How to claim your Self Assessment refund
What you need to do depends on whether you asked for the repayment on your return:
| Your situation | What happens |
|---|---|
| You completed the refund section of your return | HMRC will usually refund you automatically, to the bank account on your return |
| You did not ask for a refund on your return | Claim it through your HMRC online account |
| You are not sure | Check the 'If you have paid too much tax' section of your return |
| You have tax due in the next 45 days | HMRC may deduct the overpayment from that tax instead of repaying it |
| You paid HMRC by card | HMRC will always try to refund to that card first |
Claiming in your online account
- Sign in to your Self Assessment account to see if you are owed a refund.
- Choose 'Request a Repayment' and follow the instructions.
- If you use a personal tax account or business tax account instead, choose 'Claim a tax refund'.
HMRC only pays refunds into UK bank accounts. If you do not have one, you can sign in to your tax account and nominate someone else to receive the money or cheque. If you do not have an online account, you can set one up or contact HMRC (GOV.UK refund tool). Our guide to the HMRC personal tax account covers signing in.
How long a Self Assessment refund takes
GOV.UK says you will usually get your refund within 2 weeks of making your claim. If you asked for it on your return, that is usually within 2 weeks of sending the return online, or of the date on your SA302 tax calculation letter if you sent a paper return (GOV.UK).
- Security checks can delay a refund by up to 12 more weeks.
- Contact HMRC if you have not received it after waiting 14 weeks in total.
- While HMRC processes it, the refund may still show as available credit in your account.
- If you got a submission reference, do not request the refund again, as this can cause a delay.
- A status of 'pending' in your online account means the refund has been created but still needs to be approved and paid.
Reduce your payments on account instead of waiting
If you already know this year's tax will be lower than last year's, you can ask HMRC to reduce your payments on account before you pay them, rather than overpaying and claiming the money back later. You can apply if your business profits or other income go down, the tax relief you are entitled to goes up, or the tax deducted at source is more than in the previous year (GOV.UK).
- Online: sign in, view your latest Self Assessment return and select 'Reduce payments on account'.
- By post: fill in form SA303 and send it to HMRC.
- You must claim by 31 January after the end of the tax year, so by 31 January 2027 for 2025/26 payments on account.
Be careful not to reduce them too far. If your bill turns out higher than expected, HMRC charges interest on the difference. HMRC's late payment interest rate is 7.75% from 9 January 2026, according to its interest rates page checked on 17 September 2026. Paying late can also lead to penalties, covered in our guide to the Self Assessment late filing penalty.
What happens to a credit on your account
Payments you have made show as 'CR' on your Self Assessment statement, and a refund being processed may show as available credit in your online account. If tax is due within the next 45 days, HMRC may use the credit against it rather than repaying it. Otherwise you can ask for the credit to be repaid through your online account using the steps above. If you make weekly or monthly payments through a Budget Payment Plan and end up in credit, you can also ask for a refund (GOV.UK).
If you used provisional figures and later find you overpaid, you will get interest paid to you (GOV.UK). HMRC's repayment interest rate is 2.75% from 9 January 2026, set at base rate minus 1% with a lower limit of 0.5% (GOV.UK interest rates).
If you find an overpayment later
If a return you have already filed was wrong, you can correct it within 12 months of the Self Assessment deadline, and your bill updates to show whether you owe less. After that, you can write to HMRC to claim overpayment relief up to 4 years after the end of the tax year concerned (GOV.UK). Our guide to amending a Self Assessment tax return covers both routes.
Be wary of messages about refunds: HMRC does not send details of tax refunds by email.
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