UK tax authorities have sent tax warning letters to over 81,000 crypto holders, marking a threefold increase compared to last year.

According to Protos, HM Revenue and Customs (HMRC) sent over 81,000 warning letters to cryptocurrency holders suspected of owing taxes during the 2025/2026 fiscal year, nearly tripling the 27,714 dispatched in 2024. HMRC believes most of the unpaid taxes stem from capital gains realized during the bull market from 2022 to 2025. The letters remind users that selling, gifting, exchanging, or spending cryptocurrencies may trigger capital gains tax obligations, with violators facing penalties of up to 100% of the tax owed plus interest, and stricter penalties applying to offshore transfers. Additionally, HMRC expects to gain new powers next year to compel foreign crypto platforms to disclose user information, projecting an additional £3.15 billion in tax revenue by 2030.