Between July 2026 and March 2027, HMRC’s Wealthy and Mid-sized Business Compliance team will contact individuals it believes may have underpaid income tax or capital gains tax (CGT) arising on transactions in cryptoassets.

HMRC may contact taxpayers by letter, email or text message (SMS), and is exploring the possibility of sending one-to-many messages through the HMRC app. HMRC’s OTM activities will also include an advertising campaign on social media to help educate taxpayers about the tax implications of transactions in cryptoassets.  

The letter explains the circumstances in which transactions in cryptoassets may give rise to taxable income or chargeable gains. Where the taxpayer has income or gains to report, they should:   

• amend their self assessment tax return for the tax year in question; or
• where they are too late to amend their return, use HMRC's disclosure service. 

Generally, a taxpayer has 12 months from the deadline for filing their return to make an amendment, for example, by 31 January 2027 for the tax return for the 2024/25 tax year. As explained in a previous article, the tax return for 2024/25 and subsequent tax years includes new boxes for recording capital gains and losses on cryptoassets separately from gains and losses on other assets.  

HMRC will charge interest on any tax paid late. If HMRC finds that the taxpayer failed to report income and gains, it could charge a penalty of up to 100% of the tax due.  

No action is required where the taxpayer believes they do not have any income or gains to report. 

Taxpayers who have questions about making an amendment or a disclosure, or who want to give HMRC information about their cryptoasset transactions, can contact HMRC using the details provided in the letter.  

Agents will receive copies of letters sent to their client.