Key takeaways
- Gains on UK residential property must be reported and the tax paid within 60 days of completion.
- Other gains go on your Self Assessment return, with tax due by 31 January after the tax year.
- If you are not in Self Assessment, the real-time CGT service lets you report by 31 December after the tax year and pay by 31 January.
- Self Assessment filers must report disposals if total proceeds exceed £50,000, even if gains are below the allowance.
- Capital losses must be reported within four years of the end of the tax year to be used.
HMRC does not send a Capital Gains Tax (CGT) bill. You work out whether you have a gain, report it and pay. Which route you use depends on what you sold and whether you already file a Self Assessment return.
Do you need to report?
You need to report a gain if your total taxable gains for the year are above the £3,000 annual exempt amount.
You also need to report, even with no tax due, if:
- you are registered for Self Assessment and the total proceeds of chargeable assets you disposed of in the year were more than £50,000 (from 2023/24)
- you want to claim a capital loss, so it can be used later
- you are a non-UK resident who disposed of UK land or property
The three ways to report
| Situation | How to report | Deadline |
|---|---|---|
| UK residential property sold with CGT due (UK residents) | Capital Gains Tax on UK property account | Report and pay within 60 days of completion |
| You file Self Assessment | On the capital gains pages of your return | File and pay by 31 January after the tax year |
| You do not file Self Assessment | HMRC’s real-time Capital Gains Tax service | Report by 31 December after the tax year; pay by 31 January |
UK residential property: the 60-day return
If you sell a UK residential property that is not fully covered by private residence relief, and CGT is due, you must report and pay within 60 days of the completion date (not exchange).
- Create a Capital Gains Tax on UK property account through GOV.UK (an agent can do this for you).
- Enter the details of the property, dates, sale price, costs and reliefs.
- Pay the estimated tax using the payment reference from the return.
The 60-day figure is an estimate based on your expected income for the year. If you file Self Assessment, include the gain again on your return; any difference is paid or repaid through the return.
Self Assessment
Use the capital gains summary pages (SA108) to report each disposal, with computations for property, shares and other assets. Attach or keep computations showing how you worked out the gain, including costs and reliefs claimed.
The real-time CGT service
If you do not file a Self Assessment return, you can report gains on other assets, such as shares, using the real-time service as soon as you have made the disposal. You must report by 31 December after the end of the tax year and pay by 31 January. For a gain in 2025/26, that means reporting by 31 December 2026 and paying by 31 January 2027. If you later need to file Self Assessment for that year, report the gain on the return instead.
Paying
- 60-day returns: pay within 60 days of completion using the reference on the return.
- Self Assessment and real-time service: pay by 31 January after the tax year.
CGT is not included in Self Assessment payments on account. Late payment brings interest at the Bank of England base rate plus 4%, and penalties.
Records to keep
For each disposal, keep:
- purchase and sale contracts, completion statements and valuations
- invoices for buying and selling costs and capital improvements
- for shares, contract notes and records of all purchases and sales in the same company, to apply the matching rules
- records of any reliefs claimed, such as private residence relief or Business Asset Disposal Relief
Keep them for at least as long as for your tax return, and for assets you still own, for as long as you hold them.
Reporting losses
Losses reduce gains in the same year and can be carried forward indefinitely, but only if you report them to HMRC within four years of the end of the tax year in which the loss arose. See CGT loss relief.
Penalties
- 60-day returns: a late return attracts a £100 penalty, with further penalties at 6 and 12 months, plus interest on tax paid late.
- Self Assessment: the normal late filing and late payment penalties apply; see Self Assessment deadlines.
- Errors: inaccuracy penalties apply to careless or deliberate errors, reduced if you tell HMRC.
Frequently asked questions
How long do I have to pay Capital Gains Tax on a property sale?
60 days from completion, for UK residents selling UK residential property with CGT due.
Do I have to report a gain below the £3,000 allowance?
Not usually, unless you are in Self Assessment and your total disposal proceeds were over £50,000, or you sold UK property as a non-resident.
Is CGT included in payments on account?
No. CGT is paid in full by its due date and is not part of payments on account.
Can I use the real-time service if I file a tax return?
You should report gains on your Self Assessment return if you file one. The real-time service is for people who do not otherwise need to file.
Sources
Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance in October 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.