More than 81,000 cryptocurrency investors have been contacted by HMRC in the past year as the tax authority steps up efforts to identify people who may have failed to declare taxable crypto profits.
HMRC sent 81,172 letters, emails and text messages to cryptocurrency holders during the 2025-26 financial year, according to figures obtained through a Freedom of Information request by accountancy firm UHY Hacker Young.
Sharp increase in warnings
The figure is almost three times higher than the 27,714 warnings issued during 2023-24, as there is a growing focus on cryptocurrency and potential unpaid tax.
Investors can face tax bills and penalties if they fail to declare taxable profits from cryptocurrency transactions. This can apply not only when crypto is sold for pounds or another traditional currency, but also in certain circumstances when one cryptocurrency is exchanged for another.
Tax authority's approach
Neela Chauhan, a partner at UHY Hacker Young, said there was an expectation among tax authorities that tax evasion was widespread among cryptocurrency investors.
“A lot of the traders are young, have had little previous exposure to HMRC and often work under the assumption that HMRC has limited visibility over their activities,” she told the BBC.
HMRC said the letters were intended to help taxpayers understand their responsibilities and encourage them to review their tax affairs.
An HMRC spokesperson said: “We’re committed to helping people pay the right amount of tax, and the vast majority do.
“We regularly send letters to educate, remind or prompt customers to review their tax affairs, including customers who use crypto assets.”
Focus on historic gains
The crackdown comes despite the recent fall in the value of major cryptocurrencies such as Bitcoin and Ethereum.
HMRC said it is particularly interested in gains made during the period when cryptocurrency prices surged. Bitcoin rose sharply between December 2022 and October 2025, climbing from around £14,000 to approximately £90,000 at its peak. Anyone who bought cryptocurrency at a lower price and subsequently disposed of it at a profit may have a capital gains tax liability, depending on their circumstances and the relevant tax rules.
Accountants are now urging cryptocurrency investors to review their records and establish whether they have correctly reported their transactions.
New international rules ahead
The pressure on investors is expected to increase further from March 2027, when new rules will require cryptocurrency platforms in dozens of countries outside the UK to share information about their customers with tax authorities.
The new international reporting requirements are designed to give tax authorities greater visibility over cryptocurrency transactions and make it harder for investors to conceal taxable activity.
HMRC has previously said the new rules will help ensure cryptocurrency investors pay the tax they owe. The tax authority estimates the changes could raise up to £315million by April 2030.
Ms Chauhan warned that once HMRC receives more detailed information from cryptocurrency platforms, investigations could become much easier.
“Once HMRC has this data, tax investigations into cryptocurrency investors will be like shooting fish in a barrel,” she said.
The development means investors who have previously assumed their cryptocurrency activity would remain difficult for HMRC to trace could face greater scrutiny.
While the price of Bitcoin has fallen substantially from its previous high and was around £48,000 at the time of the report, HMRC's focus remains on whether taxable gains were made when assets were disposed of, rather than simply on their current value.
Cryptocurrency investors who receive an HMRC warning should not ignore it. They may need to review their transaction history, calculate any taxable gains and correct their tax affairs where necessary.
