Once you’ve calculated your Capital Gains Tax (CGT) liability, you need to report it to HMRC and pay the tax. There are different reporting requirements depending on the type of asset and your circumstances. This guide explains how to report CGT correctly and on time for the 2026/27 tax year.
For a complete overview of CGT, see our Capital Gains Tax Guide. For more expert tax guidance, visit our homepage.
Reporting UK Residential Property
If you sell a UK residential property that is not your main home, you must report and pay CGT within 60 days of completion. This is a strict deadline.
How to Report
Use the UK Property Account
You must report the disposal using the UK Property Account on GOV.UK.
Calculate the Gain
Work out your gain and the CGT due.
Pay the Tax
Pay the CGT within 60 days.
Include in Your Tax Return
You must also include the details in your Self Assessment tax return for the relevant tax year.
Important: The 60-day deadline applies even if you have no CGT to pay (e.g., because of Private Residence Relief). You must still report the disposal.
For more on property CGT, see our guide: Property Capital Gains Tax.
Reporting Other Assets (Shares, Crypto, etc.)
For assets other than UK residential property, the reporting requirements depend on whether you already file a Self Assessment tax return.
If You File a Self Assessment Tax Return
- Report the gain in your Self Assessment tax return.
- The deadline is 31 January following the end of the tax year.
- You can report gains from shares, crypto, overseas property, and other assets.
For a guide on filing, see our How to Submit Tax Return to HMRC Online? article.
If You Don’t File a Self Assessment Tax Return
- You can use the Real-Time CGT Service to report and pay CGT without registering for Self Assessment.
- This service is available for most assets, including shares and crypto (but not UK residential property).
- You must report by 31 January following the end of the tax year.
- You can also choose to register for Self Assessment and file a return.
The Real-Time CGT Service
The Real-Time CGT Service is designed for people who don’t normally file a Self Assessment tax return but have a CGT liability.
Who Can Use It?
- You are a UK resident.
- You have gains from assets other than UK residential property.
- You are not already registered for Self Assessment.
- You do not need to report other income or gains that require Self Assessment.
How It Works
Create an Account
You need to create a Government Gateway account (if you don’t have one). See our guide: Government Gateway Explained.
Report the Gain
Enter the details of your disposal.
Calculate and Pay
The service calculates your CGT and allows you to pay online.
Keep Records
Keep a record of your submission.
Reporting Capital Losses
If you make a capital loss, you can use it to reduce your gains. You must report losses to HMRC within 4 years of the end of the tax year in which they arose.
📅 Same Year
Losses are first set against gains in the same tax year.
➡️ Carry Forward
Any unused losses can be carried forward to future tax years.
What Happens If You Don’t Report?
Failing to report CGT can result in penalties and interest.
- Penalties: HMRC can charge penalties for late reporting and late payment.
- Interest: Interest is charged on late payments.
For more on penalties, see our guide: Late Filing Penalties.
Record Keeping
To report CGT correctly, you need to keep good records:
📄 Purchase documents
Contracts, receipts, and valuations.
📄 Sale documents
Contracts and receipts for selling costs.
🔨 Improvement records
Receipts for any capital improvements.
📊 Broker statements
For share and investment transactions.
₿ Crypto records
Transaction histories for cryptoassets.
You must keep these records for at least 5 years after the 31 January filing deadline.
How We Can Help
Reporting CGT can be complex, especially with the different deadlines and services. Our ACCA-qualified accountants can:
- Calculate your CGT liability accurately.
- Help you report CGT using the correct service.
- Ensure you meet all deadlines.
- Prepare and file your tax return.
Let us handle your CGT reporting so you can focus on your investments.
📚 Related Guides
• Capital Gains Tax Guide
• Property Capital Gains Tax
• Capital Gains Allowance
• Selling Shares Capital Gains Tax
• Crypto Capital Gains Tax
• Capital Gains Tax Calculator
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