Offsetting overpaid CGT
Many people are looking to file their tax return early for 2020/21. However, an issue has come to light where a 30-day capital gains tax (CGT) return has also been filed during the year. What’s the issue and the solution?
Since April 2020 anyone who makes a chargeable gain on a UK residential property where there is a tax bill must report the gain and pay an estimate of the tax to HMRC within 30 days of completion. This tax return requires the seller to estimate their income in order to apply the appropriate rate of CGT. The actual level of income is often not known until the end of the tax year. In light of the pandemic, it’s easy to see how someone filing a 30-day CGT tax return might have assumed all the gain would be taxed at 28%, but on reflection some is taxable at 18% instead. More information about 30-day reporting is available here.
As the gain must also be reported on the self-assessment tax return, it seems reasonable to assume that any overpayment would be sorted out once the return is filed. However, it transpires that HMRC’s computer system does not offset the overpaid amount automatically. In order to get the tax offset, there are two options:
- amend the 30-day return to correct the amount before the tax return is filed. This sorts out the overpayment, albeit separately to the main tax return;
- or if the return has already been filed, contact HMRC directly to request a manual offset. The problem is known to HMRC’s officers and so should be done swiftly. This can be done by the taxpayer, or by their accountant or tax advisor.
Note. An amendment cannot be made due to losses that were realised later on in the tax year, even if these absorb the gain in full. In these circumstances, requesting a manual offset will be the only option.
Related Topics
-
Payment deadline for corporation tax
-
HMRC targets undeclared consultancy income in the medical sector
HMRC is writing to people working in the medical sector where information supplied by private healthcare providers suggests that consultancy fees may have been omitted from their tax returns. Recipients have 30 days to check their position and respond. What should you do if you get a letter?
-
MONTHLY FOCUS: BUSINESS AND AGRICULTURAL PROPERTY RELIEF: WHAT DO THE NEW IHT RULES MEAN FOR YOU?
The inheritance tax treatment of businesses and farms changed fundamentally from 6 April 2026. The amount that can qualify for 100% business property relief and agricultural property relief is now capped, potentially leaving families with a significant tax bill for the first time. What has changed, and what should business owners and farmers be doing about it?




This website uses both its own and third-party cookies to analyze our services and navigation on our website in order to improve its contents (analytical purposes: measure visits and sources of web traffic). The legal basis is the consent of the user, except in the case of basic cookies, which are essential to navigate this website.