How do I get a Self Assessment tax refund?

If you paid more than your bill, say through 2026-27 payments on account, the extra shows as credit in your HMRC online account. Claim it there. If tax is due within 45 days, HMRC may take it off that bill.

Tradespeople overpay for ordinary reasons: payments on account based on a better year, an amended return that lowers the bill, or the same payment made twice. The rules below follow GOV.UK as checked on 17 October 2026.

How an overpayment shows up

Sign in to your HMRC online account and look at your Self Assessment statement. Money you have paid that is more than you owe shows as credit. If you asked for a repayment in your tax return and gave bank details, GOV.UK says HMRC will usually refund you automatically. If you did not, you have to claim it.

If you correct a return and the bill goes down, GOV.UK says you see the amended bill straight away online and may be able to claim a refund.

A worked example

A plasterer in England made £40,000 profit in 2025-26 and £30,000 in 2026-27, with no other income. Both years use a £12,570 Personal Allowance, 20% basic rate Income Tax and 6% Class 4 National Insurance on profit between £12,570 and £50,270.

Payments on account apply because the 2025-26 bill was over £1,000 and none of it was paid outside Self Assessment. GOV.UK says you do not need them if last year's bill was under £1,000, or if more than 80% was paid outside Self Assessment.

Payments on account towards 2026-27 are each half of the 2025-26 bill: £3,565.90 on 31 January 2027 and £3,565.90 on 31 July 2027, £7,131.80 in all. Once the 2026-27 return is filed, the bill is £4,531.80, so £2,600.00 was overpaid (£7,131.80 minus £4,531.80).

Payments on account towards 2027-28 are each half of the 2026-27 bill, unless you reduce them: £2,265.90 due 31 January 2028 and £2,265.90 due 31 July 2028. Claim in the 45 days before 31 January 2028 and HMRC may take the first £2,265.90 off the credit and repay £334.10. In our reading, claim earlier and you may get the full £2,600.00 back, with the January payment still to make. This is an example only. Your own figures will differ.

Had the plasterer reduced the payments on account to match a £4,531.80 bill, each would have been £2,265.90, and there would have been nothing to claim back.

How HMRC pays you

• HMRC only pays refunds into UK bank accounts. With no bank account, you can nominate someone else in your online account to receive the money or a cheque.
• If you asked for the refund in your return and paid by card, GOV.UK says HMRC will always try to refund that card first, even if you gave other bank details, for security reasons.
• GOV.UK lists the repayment interest rate as 2.75% a year from 9 January 2026, set at Bank of England base rate minus 1%, with a 0.5% floor.

Refunds under Making Tax Digital

HMRC says Making Tax Digital for Income Tax (MTD) does not change how you pay or the dates you pay. Quarterly updates are summaries, not payments, and your tax return still sets the year's bill. The difference is the refund: GOV.UK says you cannot claim it in an MTD tax return. You request it separately through your HMRC online services account.

If you are a CIS subcontractor

Before you join Making Tax Digital, over-deducted CIS is claimed back through your Self Assessment tax return. Once you are in Making Tax Digital, HMRC adds your CIS deductions to your tax return, and any refund is requested separately through HMRC online services. Either way, the sooner after 5 April the return is filed, the sooner HMRC can repay you. The CIS refund guide has the detail.

What this means for you

Check your statement after you file, and claim any credit you do not need for a bill due soon. Nobody can tell you the day a refund will land: GOV.UK says it usually takes 2 weeks, and security checks can add up to 12 more. In our reading, it is better not to overpay at all: GOV.UK says you can ask HMRC to reduce your payments on account if you know your tax will be lower, though interest is charged if you reduce them too far.

Missed something in an older year? You can amend a return within 12 months of its deadline. After that, write to HMRC claiming overpayment relief, up to 4 years after the end of the tax year.

Ignore any text, email or call about a refund. GOV.UK says HMRC never tells you about a tax rebate that way.

Steps to get your refund

1. Sign in to your HMRC online account and check your Self Assessment statement for credit.
2. If you file online, choose "Request a Repayment". In a personal or business tax account, choose "Claim a tax refund".
3. Give UK bank details, or nominate someone to receive the money.
4. If you have no online account, set one up or contact HMRC by phone or post.
5. Do not ask twice if you have a submission reference, as GOV.UK says that can cause a delay. Contact HMRC after 14 weeks with nothing.
6. Forward any refund text to 60599 and any email to phishing@hmrc.gov.uk.

The free MTD check shows when Making Tax Digital starts for you, and the trades section has more guides.