Guide
Capital Gains Tax Reporting Deadlines 2026/27
When and how you report a capital gain depends on the type of asset you have sold. UK residential property has a strict 60-day deadline after completion. Other assets are generally reported through Self Assessment by 31 January. Missing these deadlines can result in penalties and interest.
Published by the UK Money Calculators editorial team. Last updated for the 2026/27 tax year.
UK residential property: 60-day rule
If you sell a UK residential property and CGT is due, you must:
- Report the gain using HMRC's online "Report and pay CGT on UK property" service
- Pay the estimated CGT
- Do both within 60 days of the date of completion
This 60-day rule has applied since 27 October 2021 (previously 30 days). The deadline runs from completion, not exchange of contracts.
Missing the 60-day deadline results in an automatic late-filing penalty. Interest also accrues on any unpaid tax from the 60-day point. The penalty starts at £100 for up to six months late, increasing thereafter.
Other assets: Self Assessment
For gains on shares, funds, crypto, second properties that are not UK residential, and other assets, you report through Self Assessment:
- File your Self Assessment tax return by 31 January following the end of the tax year
- Pay the CGT by the same 31 January deadline
- For 2026/27 (ending 5 April 2027), the deadline is 31 January 2028
If you do not normally complete a Self Assessment return, you may need to register with HMRC. Registration for Self Assessment has its own deadline — generally 5 October following the tax year in which the gain arose.
When you may need to report even with no CGT due
You may need to report a disposal on your Self Assessment return even if no CGT is due. As a general guide, HMRC expects disclosure if:
- Your total disposal proceeds for the year exceed four times the annual exempt amount (approximately £12,000 for 2026/27 at the £3,000 exempt amount)
- You disposed of assets that are within the CGT regime, even if the gain is covered by losses or the exempt amount
The rules around when disclosure is strictly required are nuanced. Check the current GOV.UK guidance or speak to a tax adviser if you are unsure whether a disposal needs to be reported.
Reporting a loss
Losses are claimed through your Self Assessment return. If you do not file Self Assessment, you can write to HMRC to claim a loss. The deadline to claim a loss is four years from the end of the tax year in which the loss arose. For a 2026/27 loss, the claim deadline is 31 January 2032.
Without claiming, the loss cannot be used to offset future gains. You do not have to pay anything when reporting a loss — it is purely a record-keeping exercise that protects your ability to use the loss later.
Records you need to keep
Keep the following records for at least five years after the 31 January Self Assessment deadline for the relevant year (longer if you are still using losses from that year):
- Completion statements or contract notes showing purchase and sale prices
- Solicitor invoices confirming buying and selling legal fees
- Estate agent invoices for selling costs
- Receipts for capital improvement works
- SDLT or LBTT returns (for property purchases)
- Correspondence about probate valuations (for inherited assets)
Common mistakes
- Confusing the completion date with exchange of contracts — the 60-day clock runs from completion
- Assuming the 60-day payment covers Self Assessment — you still need to include the disposal on your tax return
- Not registering for Self Assessment in time — the registration deadline can be months before the filing deadline
- Losing records from the original purchase, which are needed years later to prove your base cost
- Not claiming losses because there is no tax to pay — unclaimed losses expire after four years
Estimate your CGT before the deadline
Use the calculator to get a CGT estimate to help you prepare your 60-day payment or Self Assessment return.
Open the CGT calculator
Official sources
Frequently asked questions
When must I report a residential property CGT gain?
Within 60 days of the completion date if CGT is due. You report via HMRC's online "Report and pay CGT on UK property" service. You must also include the disposal on your Self Assessment return for the relevant tax year.
What if I make a loss on a property sale?
If no CGT is due — because the gain is a loss, or is fully covered by the annual exempt amount — you are generally not required to use the 60-day service. However, if you want to carry a loss forward, you need to claim it via Self Assessment or by writing to HMRC within four years. Check current GOV.UK guidance for specific reporting requirements based on your total proceeds.
Does the 60-day payment settle my Self Assessment bill?
The 60-day payment is a payment on account. When you complete your Self Assessment return, HMRC will calculate the final CGT liability and credit the payment already made. If you overpaid, you will receive a refund. If there is a shortfall (e.g. because your actual income that year meant a higher rate applied), you pay the difference by 31 January.
What records do I need to keep for CGT?
Keep purchase completion statements, legal fee invoices, improvement receipts, sale contracts and estate agent invoices. Retain these for at least five years after the 31 January Self Assessment filing deadline for the year of disposal. For inherited assets, also keep the probate valuation.
What if I have never filed a Self Assessment return?
You will need to register with HMRC for Self Assessment. The registration deadline is generally 5 October following the tax year in which the disposal occurred. For a 2026/27 disposal, register by 5 October 2027. HMRC will then issue a Unique Taxpayer Reference (UTR) and you can file your return by 31 January 2028.
This page is for general information only and is not financial, tax or legal advice. Reporting deadlines and requirements can change — always check current GOV.UK guidance or consult a qualified tax adviser for your specific circumstances.