HM Revenue and Customs (HMRC), the UK's tax authority, has intensified its efforts to combat tax evasion among cryptocurrency investors. In the past year, the agency issued 81,000 warning letters to individuals suspected of underpaying taxes on their digital asset investments. This represents a 25% increase from the 65,000 letters sent in the preceding year, according to data obtained by the accountancy firm UHY Hacker Young via a Freedom of Information request.
These warnings, delivered via letters, text messages, or notifications, are intended to encourage crypto holders to declare any unpaid tax before more extensive investigations commence. Tax authorities are preparing for a significant increase in probes next year, as they will begin receiving transaction data from various cryptocurrency exchanges.
While the price of Bitcoin has seen fluctuations, softening from approximately $117,000 a year ago to around $63,000 currently, tax officials suspect that substantial amounts of tax remain unpaid from the crypto asset bull run that occurred in the three years leading up to October 2025.
Similar to other assets, investors are liable for capital gains tax on profits realized when they 'dispose' of cryptocurrency. This disposal includes selling, exchanging for a different crypto asset, using it for purchases, or transferring it to another investor. Each tax year includes a £3,000 Capital Gains Tax (CGT)-free allowance. Profits exceeding this allowance are taxed at 18% for basic-rate taxpayers and 24% for higher-rate taxpayers.
"There is the expectation among tax authorities that cryptocurrency investment is rife with tax evasion," stated Neela Chauhan, partner at UHY Hacker Young. She noted that many crypto traders are young, have limited prior experience with HMRC, and may wrongly assume limited oversight of their digital activities. "Crypto investors often forget that you may still have made a taxable gain even when you are swapping one cryptocurrency for another and might not be aware that the income you can earn by lending cryptocurrencies is taxable."
HMRC is set to receive detailed transaction data on UK residents from cryptocurrency exchanges in 52 jurisdictions, including the Channel Islands, the Cayman Islands, Ireland, and the UK, by the end of May next year. This information will include investors' names, addresses, National Insurance numbers, and full transaction records. An additional 15 jurisdictions are expected to begin sharing data a year later. Ms. Chauhan remarked that once HMRC possesses this data, "tax investigations into cryptocurrency investors will be like shooting fish in a barrel."