The CGT 60-Day Reporting Deadline: Why Completion Day Starts the Clock

A landlord who sells a buy-to-let, works out the tax is due by 31 January the following year the way it always used to be, and gets on with life has already missed the deadline that actually applies. Since October 2021, a UK residential property sale with a taxable gain has to be reported to HMRC and the tax paid within 60 days of completion — not the following January, and not from exchange. Miss it, and the penalty lands whether or not there was ever much tax at stake.

The rule: 60 days from completion, not exchange

Anyone disposing of UK residential property who has a taxable gain after reliefs must submit a UK Property Disposal return through HMRC's separate online CGT on UK property service and pay an estimate of the tax due, both within 60 days of the completion date. The clock does not start at exchange of contracts, however long the gap between exchange and completion turns out to be, and it does not wait for the normal Self Assessment cycle. A sale that completes in June is reportable and payable by roughly the middle of August, regardless of when the sale contract was signed or when the seller's accountant next expected to speak to them.

This obligation sits on top of, not instead of, the seller's ordinary Self Assessment return for the year. The 60-day return and payment are essentially a payment on account, estimated using the information available at completion; the actual position is then reconciled through the Self Assessment return covering that tax year, where the estimated figure can be corrected up or down once full-year income and any other gains are known.

Who this actually applies to

UK resident individuals, trustees and personal representatives are only required to file the 60-day return where the disposal produces a taxable gain once reliefs are applied — a sale of a former main home fully covered by Private Residence Relief, or a disposal that results in a loss, does not need reporting within the 60-day window. Non-UK residents are in a materially different position: they must report every disposal of UK land, residential or commercial, and every indirect disposal of an interest in a UK property-rich company, within 60 days regardless of whether the disposal produces a gain, a loss, or is fully covered by relief. That distinction catches overseas owners who assume no gain means no obligation, which is true for a UK resident but not for them — the point covered in more detail in our guide to non-resident CGT on UK property.

Companies sit outside this regime in a different way again. A UK resident company pays tax on a property disposal through corporation tax on the normal CT600 timetable, not the 60-day return. Non-resident companies disposing of UK property are also within the scope of corporation tax on the gain, but carry their own equivalent 60-day reporting obligation unless a specific exemption applies, which is worth checking separately before assuming the deadline doesn't reach a corporate seller.

How the payment on account actually works

The tax paid with the 60-day return is an estimate, calculated using the seller's likely income for the whole tax year to determine whether gains fall in the 18% or 24% band that applies to residential property gains, after deducting the annual exempt amount and any allowable losses already realised in the year. Getting that estimate exactly right is rarely possible in August for a tax year that doesn't end until the following April, which is precisely why the figure is only ever provisional and gets trued up later. Overpaying at the 60-day stage because full-year income was hard to predict is corrected through the Self Assessment return; underpaying because the estimate was too optimistic simply means more tax falls due at the normal 31 January payment date, potentially with interest running from the 60-day deadline if the shortfall is significant.

Jointly owned property adds a step that catches people out: each owner reports and pays on their own share separately, through their own online account, using their own income estimate. A married couple who jointly sold a rental property need two separate 60-day returns, not one filed on behalf of the household, and each spouse's own marginal rate and annual exempt amount applies to their share of the gain.

Where property investors and developers get caught out

The most common trigger we see is a portfolio landlord who sells one property from a larger holding, assumes the tax question can wait until their accountant does the annual Self Assessment return months later, and only discovers the 60-day obligation once a penalty notice arrives. Because completion, not exchange, starts the clock, sales that were agreed well in advance and then complete quickly once a chain finally moves can leave very little runway between finding out completion has happened and the deadline itself — particularly over the summer, when accountants and clients alike are harder to reach.

Executors selling a property during an estate administration face the same 60-day obligation on any gain arising after the date of death, using the estate's own reduced annual exempt amount, and it is easy for this to be missed entirely when the focus during probate is on valuing and distributing the estate rather than on an in-year tax filing most personal representatives have never had to think about before. Anyone who has already been through an HMRC enquiry into a property disposal will recognise the pattern: the underlying tax position was often fine, but the missed 60-day deadline is what actually generated the penalty and the correspondence.

Common mistakes

• Counting the 60 days from exchange of contracts instead of the completion date
• Assuming full Private Residence Relief removes any need to check the position, rather than confirming the relief genuinely covers the whole gain
• Non-resident sellers assuming a loss-making or fully relieved sale doesn't need reporting, when the non-resident rule requires reporting every disposal regardless of outcome
• Jointly owned property being reported once for the couple instead of once per owner on their own share
• Treating the 60-day payment as final and not revisiting the estimate once full-year income is known at Self Assessment time
• Executors overlooking the obligation entirely because probate is the focus and the return sits outside the normal Self Assessment calendar

What this means for sellers

Anyone selling, or about to sell, a UK residential property should know the completion date before it happens and have the CGT position — reliefs, losses, likely rate band — worked out in advance rather than starting from scratch once completion lands and the clock is already running. That is especially true for portfolio disposals, where several properties selling in the same tax year each carry their own separate 60-day obligation, and for any seller who is, or might be treated as, non-UK resident, where the reporting duty applies even to sales that turn out to owe no tax at all. Building the 60-day return into the conveyancing timetable, alongside the wider planning we do around Capital Gains Tax on a property sale, is the difference between a routine filing and an avoidable penalty.

Common questions

When does the 60-day CGT reporting clock start?

The 60 days runs from the completion date of the sale, not the date contracts were exchanged. A seller who exchanged months earlier but completes today has 60 days from today to file the UK Property Disposal return and pay the estimated tax, regardless of how long the exchange-to-completion gap was.

Do I need to report a property sale if there's no tax to pay?

UK residents only need to file a 60-day return if the disposal produces a taxable gain after reliefs such as Private Residence Relief and the annual exempt amount are applied; a fully covered gain or a loss does not need reporting within 60 days. Non-UK residents have a wider obligation and must report every disposal of UK land within 60 days regardless of whether there is a gain, a loss, or full relief available.

What happens if I miss the 60-day deadline?

A late UK Property Disposal return triggers an automatic fixed penalty, with further tax-geared penalties if the return is still outstanding at six and twelve months, on top of daily interest on any tax paid late. HMRC applies these penalties even where the eventual Self Assessment return shows no further tax is due, because the penalty attaches to the missed in-year reporting deadline itself.

This article is general information, not personal tax advice, and tax rules change. Your own position depends on facts we cannot see from here — please take advice before acting on anything above.

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