UK crypto gains hit 1.38B as 240 investors report over 1M are no longer just a rumor tax authorities can wave away. HM Revenue and Customs says declared crypto capital gains jumped to £1.38 billion in 2024-25, with 240 taxpayers each reporting more than £1 million.
- 17, 600 taxpayers reported taxable crypto gains
- £1.38 billion in declared gains, on £13.8 billion of disposal proceeds
- 240 taxpayers each reported more than £1 million in gains
- CARF is set to make exchange-level reporting far harder to dodge
Those figures do not mean HMRC has a perfect map of every Bitcoin wallet, every altcoin trade, or every offshore stash. They are declared gains, what taxpayers reported through Self Assessment, not a full census of UK crypto wealth. Still, the numbers make one thing obvious: crypto profits are now big enough to matter, and the tax office knows it.
HMRC published the data on Aug. 27 as part of its annual Capital Gains Tax statistics, and it marks the first dedicated dataset for cryptoasset gains after a reporting change. In the 2024-25 tax year, Self Assessment included a separate section for crypto capital gains, giving the tax authority a cleaner view of what people are actually putting on record.
The headline split is worth spelling out. Gains are the profit after subtracting cost basis and allowable expenses. Disposal proceeds are the gross value of assets sold, swapped, spent, or otherwise disposed of in taxable events. HMRC says those disposal proceeds totaled £13.8 billion, which is very different from the £1.38 billion in actual gains.
The average gain among those who declared taxable crypto disposals was £78, 000, according to HMRC’s statistics. And the concentration at the top was striking: the 240 taxpayers reporting more than £1 million in gains accounted for £717 million of the total.
That is where the real story starts to bite. A relatively small number of people are sitting on very large gains, and that makes crypto an obvious target for a tax authority that is getting better data by the year. Not because every trader is cheating, but because a system full of transparent records is a lot less forgiving than a system built on “maybe they won’t notice.”
HMRC also said crypto compliance and education activity generated an estimated additional £168 million in Capital Gains Tax during 2024-25. That is the unglamorous side of enforcement: reminders, warnings, and plain old fear of getting caught can bring money into the books without a courtroom drama.
UK tax rules are not especially subtle here. Capital Gains Tax can apply when you make a profit on a disposal, and a disposal can include selling crypto for cash, swapping one token for another, spending crypto on goods or services, or giving it away outside exempt transfers. “I never cashed out” is not the magical shield some traders think it is. HMRC has heard that one before.
The real shift, though, is not just what HMRC already sees. It is what it will soon be able to see.
The UK began implementing the OECD’s Crypto-Asset Reporting Framework, or CARF, on 1 January 2026. CARF is a cross-border reporting standard that requires cryptoasset service providers, exchanges and similar firms, to collect customer information and transaction data, then share it with tax authorities. In plain English: if you use a platform that falls under the rules, the days of assuming your activity lives in a neat little privacy cave are numbered.
HMRC says CARF will give it visibility into crypto transactions and help tackle tax evasion and avoidance. That is the official pitch, and it is not hard to understand why governments like it. The framework is designed to stop people from shifting wealth into crypto simply because traditional account reporting rules are already tighter.
There is also a privacy tradeoff here that deserves a straight answer. CARF is not the same thing as mass surveillance, but it does expand the amount of financial data moving between exchanges and tax authorities. Supporters will say it closes a loophole. Critics will say it turns platforms into state informants with a compliance department. Both views have a point, depending on how much you trust tax agencies and how much you value financial privacy.
HMRC is already pressing harder even before the first big CARF data flows arrive. According to UHY Hacker Young, HMRC sent about 81, 000 warning letters to crypto investors suspected of underpaying taxes in the previous 12 months. That was up 25% from roughly 65, 000 a year earlier, and nearly three times the 27, 714 recorded in 2023-24.
Those letters, often called nudge letters, are meant to push people toward voluntary disclosure before the tax office escalates things. It is the bureaucratic version of saying, “We think you may owe us money, and it would be smarter to sort this out now.”
Neela Chauhan, partner at UHY Hacker Young, expects the pressure to intensify once CARF data starts flowing in earnest.
“Once HMRC has this data then tax investigations into cryptocurrency investors will be like shooting fish in a barrel, ”
“With this data and some fairly basic AI built software, HMRC will be able to identify many cryptocurrency investors who are behind on their CGT or income tax.”
That is an aggressive forecast, not a proven outcome. HMRC has not publicly laid out every tool it will use, and “AI” is one of those words that gets thrown around like confetti whenever compliance tech is mentioned. Still, the basic point is solid: more third-party data makes tax enforcement easier, not harder.
The mention of income tax matters too. In the UK, crypto can create income tax liability in some cases, such as mining, staking, or trading conducted as a business, even when capital gains treatment does not apply. So the new reporting regime is not only about people who sold their bags at a profit. It also broadens HMRC’s ability to cross-check a wider range of crypto-related income.
That reporting regime is not arriving in a vacuum. The Treasury has already put numbers on the expected payoff, projecting CARF could generate £35 million in 2026-27 and £95 million in 2027-28. Those are modest sums relative to the broader tax base, but they are still enough to show the government believes money is being left on the table.
The rollout will not happen everywhere at once. UHY Hacker Young expects HMRC to automatically receive information from crypto exchanges in 52 jurisdictions from May 31, 2027, with another 15 jurisdictions expected to join in 2028. The source also notes that the EU’s DAC8 reporting rules began on Jan. 1, 2026, with first full-year reports due in 2027.
That timing matters. A law can be on the books before the data starts arriving at scale. Implementation is one thing. Usable cross-border information is another. When that second phase kicks in, the gap between “what happened” and “what HMRC can prove” gets a lot smaller.
The compliance burden is not landing only on traders. HMRC says around 50 reporting cryptoasset service providers are currently in scope, and they will have to handle registration, customer due diligence, annual reporting, and other administrative obligations. Exchanges have spent years pitching themselves as lean, borderless, tech-driven businesses. Now they get to moonlight as unpaid data clerks for the state. Progress, apparently, comes with paperwork.
There is a serious point underneath the sarcasm. Crypto was built to make value transfer easier, faster, and harder to block. That same property also makes it easier for people to move wealth without leaving a tidy paper trail. CARF is the state’s answer to that tension: more traceability for tax purposes, less room for evasion, and more friction for anyone who thought self-custody plus silence was a foolproof disguise.
For honest users, that likely means more record-keeping and more scrutiny. For exchanges, it means heavier compliance costs. For HMRC, it means the data is becoming actionable rather than anecdotal. And for anyone still assuming crypto gains sit beyond the taxman’s reach, that is a very expensive assumption.
Key takeaways
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Why do HMRC’s crypto figures matter?
They show declared crypto wealth is large enough to matter. HMRC says 17, 600 taxpayers reported taxable crypto gains, with total gains of £1.38 billion and 240 people each reporting more than £1 million. -
What is the difference between a gain and disposal proceeds?
Disposal proceeds are the gross value of crypto sold, swapped, spent, or otherwise disposed of. A gain is the profit after costs and allowable deductions. -
What is CARF?
CARF is the OECD’s Crypto-Asset Reporting Framework, a standard that requires crypto platforms to collect customer and transaction data and share it with tax authorities. -
Does swapping one crypto for another count in the UK?
Usually, yes. A crypto-to-crypto swap can be a taxable disposal for Capital Gains Tax purposes, though the exact tax treatment depends on the facts and circumstances. -
Will CARF stop crypto tax evasion completely?
No. It should make hiding much harder, but sophisticated evasion, offshore arrangements, and some self-custody activity may still leave blind spots.
For readers wanting a deeper primer on the shifting rules, see our Global Crypto Tax Crackdown: 48 Countries Enforce New Rules and the UK Crypto Tax Guide 2024.
