Selling UK property while living overseas comes with a reporting deadline that catches out a striking number of otherwise careful people: 60 days from completion, whether or not any tax is actually due. Because the obligation is so easy to miss and the penalty regime is applied mechanically, non-resident CGT penalties are among the most heavily appealed HMRC penalties in the property tax system, and the underlying valuations are a recurring source of genuine enquiry.
Who the 60-day rule actually catches
The non-resident CGT reporting regime began on 6 April 2015, initially covering direct disposals of UK residential property by non-residents. From 6 April 2019 it was substantially widened to cover direct and indirect disposals of all UK land, residential and non-residential, and disposals made through property-rich companies (broadly, non-UK companies deriving 75% or more of their value from UK land), by non-resident individuals, trustees, personal representatives and companies. A return is generally required even where no tax is ultimately payable, for example because the disposal produces a loss, is covered by an exemption, or the gain has already been taxed under another regime. The narrow exceptions include disposals where Principal Private Residence relief fully relieves the gain, disposals with no chargeable gain due to specific exemptions, and certain pension scheme investment disposals.
The deadline itself has moved. Disposals from 6 April 2019 to 26 October 2021 had to be reported within 30 days of completion. For completions from 27 October 2021 onward, the window is 60 days. A payment on account of the tax notionally due must also be made within the same window, calculated using the rules HMRC sets out for estimating the charge, separate from the taxpayer's ordinary Self Assessment filing (if any) for the year.
The penalty structure, and why so many get appealed
Missing the 60-day deadline triggers a fixed penalty of £100 for a return filed up to six months late. A further penalty of £300, or 5% of the tax due if that is higher, applies for a return six to twelve months late, and the same again for anything over twelve months late. Daily penalties of £10 can also be charged for continued delay. Interest accrues on any unpaid tax from the 61st day after completion, independently of the penalty position.
What makes this area distinctive, and what has generated a consistent run of appeals since the rules began, is how many people who owe no tax at all still get penalised for the reporting failure itself. A non-resident selling a UK property at a loss, or one whose gain is fully covered by an exemption, can reasonably assume there is nothing to report to HMRC, precisely the assumption that would hold for most other UK tax obligations. The 60-day rule does not work that way: the filing obligation is independent of whether any tax is actually due, and a genuine, good-faith belief that "no tax owed" meant "nothing to file" is one of the most common grounds raised, and the most common ground succeeding, in appeals against these penalties.
Rebasing and the valuation disputes it produces
Because the regime only started catching non-residents' UK property gains from 2015 (residential) and 2019 (non-residential and indirect disposals), the default position rebases the property to its market value at the relevant start date, generally 5 April 2015 for direct disposals of residential property, or 5 April 2019 for non-residential property and indirect disposals through property-rich companies, so that only the increase in value after that date is normally taxable. Taxpayers can elect for an alternative computation instead, such as time-apportionment across the full period of ownership or the original historic cost, where that produces a more favourable result and the facts support it.
The rebasing valuation, a value that by definition has to be established retrospectively, often years after the relevant date, is a natural point of disagreement with HMRC, particularly for properties that have been altered, extended or where comparable sales evidence from years ago is thin. Getting a strong, contemporaneous-style valuation with clear comparable evidence at the time of filing is worth far more than trying to reconstruct one after HMRC has queried the figure.
How these cases typically unfold
Case A: The loss-making sale nobody thought needed reporting
A UK expatriate living in Singapore sells a London flat bought in 2018 for less than they paid for it, after costs, and reasonably assumes that a loss-making sale generates no UK tax obligation. No return is filed. Eighteen months later, HMRC's data matching against Land Registry disposal records flags the unreported transaction, and a penalty notice for the full escalated amount (in excess of twelve months late) arrives. Because the seller has no other UK tax history, received no advice about the reporting requirement from either their conveyancer or the estate agent, and files the overdue return (confirming the loss and nil liability) within weeks of the penalty notice, the reasonable excuse appeal succeeds in reducing the penalty substantially, though not entirely, since some delay occurred even after the underlying facts were established.
Case B: The rebased valuation HMRC didn't accept
A non-resident company disposes of a UK commercial property in 2025, relying on a 5 April 2019 rebasing valuation prepared by an estate agent rather than a RICS-qualified valuer, using two comparable sales from a different part of the same town. HMRC opens an enquiry into the NRCGT return, disputing the rebased value as unsupported and proposing a lower 2019 value based on its own comparables, which would substantially increase the taxable gain. A formal RICS valuation, commissioned specifically to address the enquiry and drawing on more closely comparable evidence from the immediate vicinity and period, narrows the gap considerably and the matter is agreed at a figure close to the taxpayer's original position, illustrating how much a properly evidenced valuation at the point of filing would have avoided the dispute in the first place.
Responding to an HMRC enquiry or penalty
Where the issue is a missed deadline with no underlying tax dispute, the priority is filing the overdue return immediately and building the reasonable excuse case around genuine, specific facts, not a general claim of not knowing the rules. Where HMRC is querying the substance of the return, a rebasing valuation, an indirect disposal calculation, or whether an exemption genuinely applies, the case is won on the quality of the evidence assembled, valuation reports, comparable evidence and a clear paper trail showing how the figures were arrived at, rather than on argument alone.
Related guides in this series
- Offshore assets investigation: full guide
- FIG regime compliance checks: the remittance basis replacement
- Statutory Residence Test enquiries
- Reasonable excuse: the complete guide
- Estimate your penalty
- Private Residence Relief: HMRC challenges to PPR claims
Frequently asked questions
Do I need to report a UK property sale to HMRC if I'm not a UK resident?
Yes, in almost all cases. Any direct or indirect disposal of UK land must be reported within 60 days of completion, with tax paid on account in the same window, even where no tax is ultimately due, subject to limited exceptions.
What is the penalty for missing the 60-day non-resident CGT deadline?
£100 fixed for up to 6 months late, then £300 or 5% of the tax due (whichever is higher) for 6-12 months late, and again for over 12 months late, plus possible daily penalties of £10 and interest from day 61.
Can a non-resident CGT penalty be appealed?
Yes, and many are successfully. Genuine unawareness of the rule, particularly in nil-gain or loss situations, combined with prompt correction once discovered, is a recognised and often successful reasonable excuse ground.
What valuation date applies for calculating a non-resident's gain?
Generally automatic rebasing to 5 April 2015 (residential, direct disposals) or 5 April 2019 (non-residential and indirect disposals), so only the post-rebasing gain is normally taxable, unless an alternative computation is elected.