The 60-Day Capital Gains Tax Clock: What Landlords Must Do the Moment a Sale Completes

Selling a UK rental property starts a strict 60-day countdown to report and pay Capital Gains Tax — separate from, and much faster than, your annual Self Assessment. Here's the deadline, the current rates and allowance, and what actually brings the bill down.

Let me ask you something: if you sold an investment property tomorrow, would you know exactly when your Capital Gains Tax is due? Most landlords assume it slots into their usual Self Assessment timetable, filed the following January along with everything else. It doesn't. Since 27 October 2021, anyone selling UK residential property at a gain has had a much shorter, much stricter clock running — and missing it costs money before you've even had time to think about the sale itself.

A 60-day deadline, not a once-a-year one

If you're a UK resident and you sell (or otherwise dispose of) a UK residential property that produces a chargeable gain, you must report that gain to HMRC and pay any Capital Gains Tax due within 60 calendar days of completion — not exchange of contracts, completion. That's done through HMRC's dedicated UK Property Reporting Service, accessed via your Government Gateway account, and it stands entirely apart from your annual Self Assessment return. You'll still need to reference the disposal on your Self Assessment later, but the 60-day report and payment happens first, on its own timetable. Miss it and HMRC can charge both interest on the tax owed and a separate penalty for the late return, regardless of whether the rest of your tax affairs are otherwise up to date.

The practical trap is timing: a property sale already involves solicitors, estate agents, and a completion date that can move. It's easy for the 60-day window to open and close while everyone's attention is on getting the keys handed over.

What you're actually taxed on, and at what rate

Capital Gains Tax is charged on the gain — sale price less what you paid for the property, less allowable costs — not on the sale price itself. Allowable costs typically include purchase and sale legal fees, estate agent fees, stamp duty paid on purchase, and the cost of capital improvements (an extension, for example) rather than routine repairs or maintenance, which aren't deductible. Every individual also has an Annual Exempt Amount that comes off the gain before any tax is calculated; this allowance has been fixed at £3,000 for individuals since the 2024/25 tax year and doesn't carry forward if unused.

On what's left, residential property gains are taxed at 18% within the basic rate band and 24% above it, based on your total taxable income for the year — so part of a large gain can fall into each band. These rates were set following the Autumn Budget 2024, which aligned the rate on other assets with the rate landlords had already been paying on property, rather than the other way around.

Reliefs worth checking before you assume the worst

If the property being sold was ever your main home, Private Residence Relief can shelter some or all of the gain for the period you lived there, plus a final nine months of ownership regardless of use. What it no longer covers, for any period after 5 April 2020, is the old "letting relief" — that only survives now if you were living in the property alongside your tenant at the time, which rules it out for most straightforward buy-to-let situations. It's a relief worth having your accountant check line by line rather than assuming either way.

Held in a limited company? Different regime entirely

None of the above applies if the property sits inside a limited company or SPV — company disposals are charged to corporation tax on the gain, reported through the company's own accounts and tax return, not the personal 60-day service. It's one more thread in the personal-versus-company ownership decision, and one reason some investors structure new purchases through a company from the outset rather than working it out retrospectively at sale.

The takeaway

The 60-day rule doesn't change what you owe — it changes how fast you need to work out what you owe. The sensible move is to start pulling together your purchase records, improvement costs, and sale figures the moment a sale is agreed, not after completion, so the actual filing is a formality rather than a scramble against the clock. If you're weighing up a sale, or thinking through how ownership structure affects the tax bill on exit, ask us a question — we're happy to point you in the right direction, or toward one of our vetted accountants for the specifics.