240 UK Crypto Millionaires Report £717M in Gains, HMRC Reveals

Britain’s tax authority just put numbers to something the crypto world had long suspected. HMRC published its first official data on taxable cryptoasset gains, and the figures are striking — 240 people declared over £1 million each in crypto capital gains during the 2024-2025 tax year, with that group alone reporting a combined £717 million.

That’s a lot of money sitting in a relatively small crowd.

The 2024-2025 Numbers in Full

Zoom out from the millionaire bracket and the picture gets bigger. Across the full 2024-2025 tax year, 17,600 individuals made cryptoasset disposals that triggered Capital Gains Tax. Total disposal proceeds hit £13.8 billion. Net gains came in at £1.38 billion. Bitcoin, Ethereum, and Dogecoin were among the digital currencies involved. And there’s a gender split baked into the data that’s pretty hard to ignore — roughly 87% of those reporting gains were male. That’s not a small skew. It’s basically the whole room.

Crypto gains aren’t taxed differently from other capital gains in the UK. Same rules, same rates. HMRC says it’s been working to make sure taxpayers actually know that, pushing education alongside enforcement.

CARF Kicks In — and the Penalties Are Real

The UK adopted the Cryptoasset Reporting Framework, known as CARF, from January 2026. It’s an OECD initiative, so it’s not just a British thing — it’s part of a wider international push to standardize how digital asset transactions get tracked and reported across borders. Stablecoin adoption and crypto usage have grown sharply across multiple jurisdictions in recent years, which made some kind of coordinated reporting framework almost inevitable.

Under CARF, UK cryptoasset service providers must report customer information directly to HMRC. That obligation kicks in starting 2027. Non-compliance carries penalties of up to £300 per user. That number sounds modest until you think about platforms with hundreds of thousands of customers — it adds up fast, and it’s clearly designed to sting.

The framework’s logic is straightforward. If HMRC can see what exchanges and service providers know about their users, it becomes a lot harder for someone to quietly sell a stack of Bitcoin and skip the tax return. Undeclared gains and income are what CARF is built to catch.

Read also: UK Tax Authority Identifies 240 Crypto Millionaires Amid $18.7 Billion in Disposals

Separately, HMRC runs a Crypto Disclosure Service on GOV.UK. It’s a channel specifically for cryptoasset owners who need to come clean on unpaid taxes — whether that’s from trading, but also mining, staking, or lending. Those activities can generate taxable income, not just capital gains, and the tax treatment differs depending on how the crypto was earned or received. Crypto received through employment, for instance, can attract Income Tax and National Insurance on top of any capital gains exposure.

Not everyone knows that. Probably a lot of people don’t.

Self Assessment Deadlines and What Holders Need to Do

For the 2025-2026 tax year, anyone with cryptoasset income or gains above the tax-free allowance needs to declare it through Self Assessment. The deadline for that return is 31 January 2027. HMRC updated the Self Assessment process to include a dedicated section for cryptoasset gains, which at least makes the reporting path clearer than it used to be. Guidance on what counts as a taxable transaction — and how to report it — is available on GOV.UK.

Worth noting: a disposal isn’t just selling crypto for pounds. Exchanging one cryptocurrency for another counts too. That catches people off guard more than almost anything else in crypto tax.

See also: Crypto Gains Reflect Fed Influence as Traders Eye Macro Signals

Service providers are now squarely in the compliance chain. They’re required to share customer data with HMRC under the new framework, which puts them in a very different position than they occupied even two or three years ago. The industry’s relative anonymity is shrinking fast. Platforms that don’t comply face those per-user fines, and HMRC seems serious about enforcement.

The broader international alignment matters here. By adopting the OECD’s CARF, the UK isn’t acting alone — it’s joining a coordinated effort to close reporting gaps that exist precisely because crypto moves across borders easily. Tax authorities in other CARF-adopting countries will be sharing data too, which makes offshore crypto holdings harder to hide.

The 240 millionaires in the dataset declared their gains. The open question is how many didn’t — and whether CARF’s reporting requirements, landing in 2027, will finally give HMRC the tools to find out. Penalties of up to £300 per user, applied across large platforms, represent a serious financial deterrent for any service provider tempted to look the other way.