Its first crypto gains table covers 17,600 taxpayers, while CARF data will begin reaching the agency in 2027.
MRC has disclosed £1.38 billion in reported UK crypto gains, with just 240 investors accounting for more than half.
The figures mark the first time HM Revenue & Customs has published crypto-specific Capital Gains Tax data, giving the agency a formal baseline before new reporting rules begin supplying it with information directly from crypto providers.
For the 2024 to 2025 tax year, 17,600 individuals reported £13.8 billion of cryptoasset disposal proceeds and £1.38 billion of gains. Of that total, 240 people who each reported more than £1 million in gains accounted for £717 million.
The data comes from a dedicated crypto section added to Self Assessment returns. It therefore captures declared Capital Gains Tax-liable disposals rather than every crypto transaction in Britain and cannot show how much activity went unreported.
The change will give the tax authority a separate dataset alongside taxpayers’ own declarations, increasing its ability to identify discrepancies between reported gains and activity recorded by crypto platforms.
The reporting timetable does not delay existing tax obligations. Crypto owners with reportable gains or income for the 2025 to 2026 tax year must still file their Self Assessment return and pay tax due by Jan. 31, 2027.
The new statistics therefore provide HMRC with a declared baseline before standardized third-party reporting begins. From 2027, the agency will increasingly be able to compare what crypto investors say they earned with what platforms say they did.