by Asim Abbas
12 November 2026 
Forgot to report a property sale or crypto gain? How to put it right with HMRC
Forgot to report a property sale or crypto gain? How to put it right with HMRC
Missed the 60-day deadline on a property sale, or never declared crypto gains? You are not alone, and it can be fixed. The key is to come forward before HMRC comes to you.
- Coming forward voluntarily usually means much lower penalties than waiting for HMRC.
- Crypto gains have their own HMRC Crypto Disclosure Service.
- How far back you go depends on behaviour: 4, 6 or up to 20 years.
- Interest runs daily from the date the tax was due.
- We calculate everything, choose the right route and make the disclosure for you.
HMRC now receives more data than ever, from property records to crypto platforms reporting under new international rules from 2026. Unreported gains are increasingly likely to be spotted.
This guide explains which disclosure route fits your situation, how far back you need to go, and how penalties and interest are worked out.
Why act now?
HMRC published crypto gains data for the first time in August 2026, and since January 2026 crypto platforms have been collecting customer information under the international Cryptoasset Reporting Framework, with data reaching HMRC from 2027 (see the HMRC announcement). For property, HMRC expects most UK sales to be reported within 60 days, and non-residents must report every UK property disposal. When HMRC finds an unreported gain first, penalties are higher and the process is harder.
Choosing the right disclosure route
- Crypto gains or income: HMRC’s Crypto Disclosure Service
- Undeclared rental income: the Let Property Campaign
- Overseas income or gains: the Worldwide Disclosure Facility
- Other UK income or gains, including an unreported UK property sale: HMRC’s general disclosure service
If an unreported property sale is recent, it may still be possible to file the late 60-day return and pay with interest. Non-residents should note that disposals made on or before 5 April 2020 can no longer be reported through the UK property service, so an older sale needs a disclosure. We will tell you which route fits.
How far back do you go?
HMRC uses your behaviour to decide:
- 4 years if you took reasonable care
- 6 years if you were careless
- up to 20 years if the error was deliberate
Check the tax on a gain
Use our free Capital Gains Tax calculator to estimate what might be owed.
What will it cost?
A disclosure is made up of three parts: the tax owed, interest from the date the tax was due, and a penalty. Penalties are a percentage of the tax, and they depend on why the tax was missed and whether you came forward before HMRC contacted you. An unprompted disclosure attracts the lowest penalties. For crypto disclosures, HMRC expects payment within 30 days of submitting; if you cannot pay in time, it is important to talk to HMRC early.
Working out the gain correctly
For property, use the full purchase and sale figures, all allowable costs and any reliefs, such as Private Residence Relief. For crypto, HMRC’s pooling rules apply, which is why exchange profit and loss figures are rarely right. Getting the gain right keeps the tax, interest and penalty as low as they should be.
Fixed-fee accountancy support
Transparent monthly packages for sole traders, landlords and limited companies. Fixed fees agreed upfront, VAT included.
Get a fixed-fee quoteCall 0161 531 4179How we handle it
- We review your records and confirm what was missed and in which years.
- We calculate the tax, interest and penalty position.
- We choose the right disclosure route and prepare the disclosure.
- We submit it with your authorisation and deal with HMRC’s questions.
If HMRC has already written to you, do not ignore the letter. See our tax investigation support, or read our voluntary disclosure guide and our guide to HMRC’s new crypto data.
What should I do next?
An unprompted disclosure usually means the lowest penalties.
Completion statements, exchange histories, bank statements and old returns.
Crypto, rental, overseas or general disclosure.
We will look into your tax affairs and sort this out with HMRC.
Frequently Asked Questions
Will I go to prison for an unreported gain?
For most people who come forward voluntarily, the outcome is paying the tax, interest and a civil penalty. Speak to us confidentially about your situation.
Can I still file a late 60-day property report?
Usually yes for recent sales, with penalties and interest. Very old disposals by non-residents may need a disclosure instead.
How far back will HMRC look?
Four years for reasonable care, six for careless errors and up to 20 years for deliberate ones.
Is there a separate route for crypto?
Yes. HMRC’s Crypto Disclosure Service is for unpaid tax on cryptoassets.
Can you deal with HMRC for me?
Yes. With your authorisation we prepare and submit the disclosure and handle HMRC’s questions.
Need help with this? Wingate Accountants offers fixed-fee online accountancy support across the UK. Call 0161 531 4179 or request a quote at wingateaccountants.co.uk.
About the Author
Asim Abbas
I’m Asim Abbas, founder of Wingate Accountants and a Chartered Certified Accountant. I help sole traders, landlords and directors stay on top of their tax with fixed fees and plain-English advice.
