The 60-Day CGT Deadline: Reporting and Paying Tax When You Sell a Rental

Most landlords assume that any tax on selling a rental property gets sorted out at the same time as the rest of their tax, on the Self Assessment return after the tax year ends. For UK residential property that assumption is wrong, and it is an expensive one. Since 6 April 2020 you have had to report the disposal and pay the Capital Gains Tax due within 60 days of completion, on a separate return, long before your annual Self Assessment is filed. It is one part of the wider picture set out in our capital gains tax and property disposals guide, and below we explain exactly how that deadline works and what it costs to miss.

What the 60-day rule actually says

The rule is short and strict. HMRC requires that you report and pay any Capital Gains Tax due on a UK residential property disposal within 60 days of the completion date, which is the date you stopped being the property owner. The official position is set out in HMRC guidance on reporting and paying Capital Gains Tax on UK property. The clock starts at completion, not at exchange, and not at the end of the tax year, so for a sale completing in, say, early summer, the deadline can fall many months before you would otherwise be thinking about tax at all.

The return is made through a dedicated Capital Gains Tax on UK property account, which is separate from your normal Self Assessment login. This catches people out because it is an extra account to set up, and an extra obligation that exists even for landlords who already file a tax return every year. The 60-day return does not replace your Self Assessment; the gain still has to be declared there as well, with the tax already paid through the property account credited against the final position.

When you do and do not need to report

You need to make a 60-day return whenever a UK residential property disposal produces a chargeable gain on which tax is due. For a buy-to-let with no main-residence history, that is the usual outcome once the gain exceeds your annual exempt amount, which is £3,000 for the 2026/27 tax year. If the gain after reliefs and the annual exemption leaves no tax to pay, there is generally no 60-day return to file, though the disposal may still need to go on your Self Assessment return.

The point to watch is that the test is about whether tax is due, not about how large the sale price is. A modest gain that still exceeds the £3,000 exemption brings the 60-day obligation into play. Because the annual exempt amount has fallen sharply in recent years, far more disposals now cross that line than did a few years ago, so landlords who sold without a 60-day return in the past should not assume the same applies today.

What you need ready before completion

Sixty days sounds generous until you try to compute a gain from scratch with the clock already running. The gain is the sale proceeds less the original purchase price, the buying and selling costs, and any qualifying capital improvements, and every one of those figures needs supporting evidence. The mechanics of that calculation are covered in the capital gains tax for landlords guide, and the wider disposal picture in the selling a rental property tax guide.

• The original purchase price and completion statement, plus the Stamp Duty and legal fees paid on acquisition.
• Evidence of capital improvements, such as an extension or a loft conversion, kept separate from routine repairs which do not reduce the gain.
• The selling costs, including estate agent and conveyancing fees.
• Any periods that qualify for Private Residence Relief or lettings relief if the property was ever your home.
• An estimate of your income for the year, since that determines how much of the gain is taxed at the lower rate.

Pulling these together after completion, against a deadline, is where mistakes and missed reliefs happen. Gathering them before you exchange means the return is a formality rather than a scramble.

How much tax, and at what rate

For a residential investment property the gain is taxed at 18 percent to the extent it falls within your remaining basic-rate band and 24 percent on the part above it, after deducting the £3,000 annual exempt amount. Because the gain stacks on top of your income, a large gain often uses up the basic-rate band quickly and falls mostly into the 24 percent rate. Higher and additional rate taxpayers pay 24 percent on the whole gain. These rates apply from 6 April 2026 and are confirmed in HMRC guidance.

A worked outline shows why the 60-day timing bites. Take a property bought years ago and sold now at a gain well into six figures. After the £3,000 exemption, most of that gain is likely to be taxed at 24 percent, producing a tax bill of tens of thousands of pounds, all of which must be reported and paid within 60 days of completion. That is a significant sum to find quickly, which is why landlords are well advised to set the expected tax aside from the sale proceeds rather than spend or reinvest them first.

What happens if you miss the deadline

Missing the 60-day window is not a soft deadline. HMRC charges an initial fixed penalty of £100 as soon as the return is late, with further penalties building up the longer it remains outstanding, and interest runs on any tax paid late from the original due date until you pay. The penalties escalate at set intervals once the return is several months overdue, so a forgotten 60-day return can quietly grow into a meaningful additional cost on top of the tax itself.

The professional bodies have repeatedly flagged how easily this deadline is missed, particularly by people who sell a single property and have never encountered the rule. The ICAEW guidance on CGT UK property disposal reporting sets out the practical pitfalls and confirms that the obligation applies even where the taxpayer is already within Self Assessment. The safest course is to treat the disposal as a tax event the moment a sale is agreed, not the moment you next think about your annual return.

Common questions about the 60-day CGT return

Does the 60 days run from exchange or completion?

From completion. The deadline is 60 days from the date you stopped being the property owner, which is the completion date, not the earlier exchange of contracts.

I already file a Self Assessment return, do I still need the 60-day return?

Yes. The 60-day return is a separate obligation that exists alongside Self Assessment. You report and pay the tax within 60 days through the dedicated property account, then also declare the disposal on your annual Self Assessment return, with the tax already paid credited against the final figure.

What if there is no tax to pay after reliefs?

If the gain after reliefs and the £3,000 annual exempt amount leaves no Capital Gains Tax due, there is generally no 60-day return required, although the disposal may still need to appear on your Self Assessment return. Where any tax is due, the 60-day return applies.

How is the tax paid?

Through the Capital Gains Tax on UK property account, which is separate from your normal Self Assessment login and has to be set up specifically for this purpose. Both the report and the payment are due within the 60 days.

The 60-day deadline is one of the easiest landlord obligations to miss and one of the more costly, because the penalties and interest start immediately and the calculation cannot be rushed without losing reliefs. If you are selling a rental property in Harrow, the safest approach is to have the gain worked out before completion so the return is ready to file. Send us the property details through the form below and we will calculate the gain, confirm the tax, and handle the 60-day reporting so the deadline never becomes a problem.