Britain's tax authority has for the first time published separate data on cryptocurrency capital gains, revealing that 17,600 taxpayers reported taxable crypto gains totaling £1.38 billion during the 2024-25 tax year.

The disclosure from HM Revenue & Customs follows the introduction of a dedicated cryptoasset section in Self Assessment tax returns, a change that for the first time separates digital asset disposals from other chargeable assets on the form.

Million-Pound Gains Lead the Way

Among those taxpayers, 240 individuals each reported more than £1 million in crypto capital gains. Together, this group accounted for £717 million of the total — meaning the top 240 taxpayers generated more than half of all reported crypto gains for the year.

The average gain across all 17,600 taxpayers stood at about £78,000. Taxpayers also reported £13.8 billion in proceeds from cryptoasset disposals. HMRC counts several transaction types as disposals, including selling crypto, swapping one digital asset for another, and using crypto to purchase goods or services. The data covers assets including Bitcoin, Ethereum and Dogecoin.

The tax year covered by the figures, which ran from April 2024 to April 2025, spanned a period in which digital asset prices hit new highs: Bitcoin crossed $100,000 for the first time in December 2024 and set a record above $109,000 in January 2025. More disposals also became reportable because the capital gains tax-free allowance, the Annual Exempt Amount, was cut to £3,000 for individuals from April 2024, down from £6,000 the previous year and £12,300 two years earlier. The Autumn 2024 Budget additionally raised the main Capital Gains Tax rates from 10% and 20% to 18% and 24%, the rates at which crypto gains are taxed depending on a taxpayer's income.

Tax Enforcement Set to Intensify

The new figures arrive as HMRC expands its ability to track crypto activity. The agency said crypto investors should report taxable gains above the applicable tax-free allowance. HMRC has in previous years sent "nudge letters" to people it identified as potentially holding cryptoassets, prompting them to check whether they owed tax.

HMRC also said its compliance and education work generated an estimated additional £168 million in Capital Gains Tax during 2024-25.

International reporting rules are set to give the tax authority further visibility. Under the Cryptoasset Reporting Framework, developed by the OECD and backed by dozens of jurisdictions, service providers will report customer information to tax authorities, and HMRC is expected to begin receiving that data in 2027. The mechanism mirrors the automatic exchange of financial account information that already operates between tax authorities under the Common Reporting Standard.

Demographic data also highlights the profile of reported crypto investors: around 87% were men, while 13% were women. The 17,600 filers represent a small share of those exposed to crypto: Financial Conduct Authority research has estimated that around 7 million UK adults hold cryptoassets.

The latest figures suggest that large crypto gains have become a meaningful part of Britain's capital gains tax landscape. They also signal a more closely monitored environment for digital asset investors as tax authorities gain access to broader transaction data.