The UK tax authority, HM Revenue & Customs (HMRC), has significantly increased its efforts to ensure crypto investors comply with tax regulations. In the 2024–25 tax year, HMRC issued nearly 65,000 warning letters, known as "nudge letters," to individuals suspected of underreporting or evading taxes on digital asset gains. This marks a substantial rise from the 27,700 letters sent the previous year, highlighting HMRC's intensified focus on crypto-related tax compliance. The surge in warning letters comes as the Financial Conduct Authority reports that seven million UK adults now own cryptocurrencies, reflecting a growing interest in digital assets. HMRC's ability to monitor the market has improved, with the agency now receiving transaction data from major crypto exchanges and set to gain automatic access to global exchange data from 2026 under the OECD's Crypto-Assets Reporting Framework.