HM Revenue & Customs (HMRC) has issued approximately 81,000 warning letters to cryptocurrency holders as part of a significant tax crackdown. This number represents a nearly threefold increase since 2024, according to data obtained via a Freedom of Information request. The campaign aims to recover unpaid capital gains taxes from the surge in cryptocurrency values.
During a period between December 2022 and October 2025, the value of major cryptocurrencies like Bitcoin saw substantial increases. Bitcoin, for instance, rose from around £14,000 to approximately £90,000 within this timeframe. Although Bitcoin's price has since fallen to about £48,000, HMRC suspects that considerable amounts of capital gains remain undeclared.
Accountants are advising investors to review their tax obligations, as HMRC is set to gain enhanced powers that will facilitate targeting individuals with unpaid taxes. Beginning in March 2027, cryptocurrency platforms operating in numerous countries outside the UK will be mandated to share customer data with tax authorities. HMRC stated that these forthcoming measures are intended to ensure that "crypto bros pay their fair share of tax."
The tax office estimates that these changes will generate up to £315 million by April 2030. HMRC has highlighted that this figure is equivalent to the annual cost of funding over 10,000 newly qualified nurses. Experts warn that with the incoming data, tax investigations into cryptocurrency investors will become significantly more straightforward for HMRC.