HMRC: 240 Crypto Millionaires Filed in 2024/25

HMRC has published its first dedicated breakdown of cryptoasset capital gains, and the numbers are striking. In the 2024 to 2025 tax year, 240 people each declared over £1 million in crypto gains, with that group alone reporting £717 million between them. For anyone who has traded, sold, or swapped crypto in the UK, these figures are a signal that HMRC is watching closely and that the window to get your position right is narrowing fast.

What the New HMRC Data Actually Shows

The statistics, published as part of HMRC's annual Capital Gains Tax release, are notable for two reasons. First, it is the first time HMRC has isolated cryptoasset gains as their own category, made possible by the introduction of a dedicated cryptoasset section on the Self Assessment return. Second, the scale of reported gains is significant enough to drive real enforcement interest.

The headline numbers

Across the 2024 to 2025 tax year, 17,600 individuals made Capital Gains Tax-liable disposals of cryptoassets, covering Bitcoin, Ethereum, Dogecoin, and other tokens. Together, they reported:

• Total disposal proceeds of £13.8 billion
• Total gains of £1.38 billion
• An average gain of £78,000 per individual

The 240 highest earners accounted for £717 million of that £1.38 billion total, meaning roughly half of all declared cryptoasset gains sat with fewer than 1.4% of the filers.

Who is filing?

The data also reveals a notable gender split: around 87% of individuals reporting cryptoasset gains were male, with women making up approximately 13%. HMRC has not offered an explanation for this disparity, but it aligns with broader patterns in crypto ownership reported across other jurisdictions.

Why HMRC Published This Now

This release is not just a statistical exercise. HMRC has been running targeted upstream compliance work on cryptoassets since late 2023, including social media campaigns and updated GOV.UK guidance, aimed at encouraging voluntary disclosure before enforcement becomes necessary. The department estimates that this activity generated an additional £168 million in Capital Gains Tax in 2024 to 2025 as a direct result.

The compliance message is deliberate

Publishing specific data on crypto millionaires serves a clear purpose: it signals to holders who may have underreported that HMRC has both the data and the intent to act. The accompanying ministerial comment made the point directly, noting that taxes are due on cryptoasset gains just as they are on any other gains, and that ensuring people understand their obligations is central to closing the tax gap.

The timing also matters. International reporting infrastructure is being put in place right now, and once it is operational, HMRC's ability to detect undeclared gains will increase substantially. Publishing these figures ahead of that change reinforces the case for voluntary compliance.

CARF: The Reporting Framework That Changes Everything

The most consequential part of the announcement sits in a brief paragraph near the end of the HMRC release, but it deserves close attention. From January 2026, the UK began implementing the Cryptoasset Reporting Framework, known as CARF, an international standard developed by the OECD. HMRC will start receiving data from cryptoasset service providers under this framework from 2027.

What CARF means in practice

Under CARF, exchanges, brokers, and other cryptoasset service providers operating in participating jurisdictions will be required to collect and report customer information to their local tax authority. That authority then shares the data with HMRC if the customer is UK-resident. The effect is similar to what the Common Reporting Standard already does for offshore bank accounts: HMRC gets a direct feed of transaction data from platforms, whether those platforms are UK-based or not.

Service providers that fail to comply with their CARF obligations may face penalties of up to £300 per user. For a large exchange with millions of UK customers, non-compliance becomes very costly very quickly, which means the industry has a strong incentive to report fully and accurately.

What this means for you before 2027

If you've been treating overseas or smaller exchanges as a reporting blind spot, CARF closes that gap. The practical implication is that any gains or income you haven't declared for years prior to 2027 are more likely to surface once HMRC starts cross-referencing CARF data against Self Assessment returns. Voluntary disclosure now, before that data arrives, is a meaningfully better position than being identified through a data match.

Which Transactions Trigger a UK Crypto Tax Liability

Not every crypto transaction creates a tax bill, but far more of them do than many holders realise. HMRC's guidance distinguishes between disposals that may give rise to Capital Gains Tax and receipts that may give rise to Income Tax and National Insurance.

Capital Gains Tax events

A disposal occurs when you:

• Sell cryptoassets for cash
• Exchange one cryptoasset for a different type (for example, swapping Bitcoin for Ethereum)
• Use cryptoassets to pay for goods or services
• Give cryptoassets away to another person, other than as a gift to a spouse, civil partner, or charity

Each of these events requires you to calculate the gain or loss using HMRC's approved pooling rules, and to report it if the total proceeds or gains exceed the relevant annual exempt amount.

Income Tax and National Insurance events

Cryptoassets received in the following ways are treated as income rather than capital gains, and are subject to Income Tax and, where applicable, National Insurance contributions:

• Cryptoassets received as employment income
• Earnings from self-employment paid in crypto
• Mining rewards
• Staking rewards
• Lending income

There is currently no dedicated Self Assessment box for cryptoasset income such as mining or staking. These amounts are reported through existing Income Tax provisions, which means they can be easy to overlook if you're completing the return yourself.

Key Deadlines for the 2025/26 Tax Year

The 2024 to 2025 figures HMRC has just published relate to a tax year that has already closed. But the next filing cycle is already under way. For the 2025 to 2026 tax year, anyone with cryptoasset income or gains above the relevant tax-free allowances must declare them through Self Assessment and pay any tax owed by 31 January 2027.

What to do if you have undeclared crypto gains

HMRC operates a disclosure facility on GOV.UK that allows individuals to declare unpaid tax from cryptoassets. Using the facility voluntarily, before HMRC contacts you, typically results in lower penalties than if HMRC opens an enquiry first. Given that CARF data will start flowing to HMRC from 2027, the calculation is straightforward: disclosure now is almost always preferable to being identified through a data match later.

If you're unsure whether you have a liability, HMRC's GOV.UK guidance sets out the full range of scenarios, from straightforward sales to more complex situations involving DeFi protocols and staking arrangements. For anything above a simple buy-and-sell, professional advice is worth considering, particularly given the average gain of £78,000 per filer that the new data reveals.

Practical Steps for UK Crypto Holders

The combination of published data, CARF implementation, and active compliance messaging from HMRC points in one direction. Here's what to do now.

Review your transaction history

Pull complete records from every exchange, wallet, and DeFi platform you've used. Every disposal needs a cost basis, a disposal value, and a date. Without these, accurate calculation of your crypto tax in the UK is not possible, and estimated figures are not accepted by HMRC.

Calculate your gains and losses correctly

HMRC requires pooling under the share identification rules, which group acquisitions and disposals in a specific order. Getting this wrong is one of the most common errors on crypto Self Assessment returns. A reliable crypto tax calculator that applies UK pooling rules will save significant time and reduce the risk of errors that trigger queries.

Check earlier years

The current HMRC data covers 2024 to 2025, but crypto disposals in earlier tax years that were not declared remain open to enquiry. If you traded actively in 2021 or 2022 during the bull market, those gains should have been reported in the 2021/22 or 2022/23 returns. Reviewing those years now, before CARF data arrives, is prudent.

Consider Making Tax Digital obligations

If you have income from crypto alongside other self-employment or property income, you may already be within the scope of Making Tax Digital for Income Tax. HMRC has begun auto-enrolling some taxpayers into MTD for Income Tax, and missing a quarterly update deadline carries its own penalties. Check your enrolment status if you haven't already.

It's also worth noting that HMRC has been sending large volumes of nudge letters to crypto holders. If you've received one, or want to understand what genuine HMRC contact looks like, HMRC sent 81,000 crypto warning letters in 2025/26, and the volume is unlikely to decrease as CARF data comes online.

Source: GOV.UK / HMRC

Frequently Asked Questions

Do I need to pay tax on crypto in the UK even if I didn't cash out to pounds?

Yes. HMRC treats a swap between two different cryptoassets, for example exchanging Bitcoin for Ethereum, as a disposal. You calculate the gain or loss based on the sterling value at the point of the exchange. Staying "within crypto" does not defer your CGT liability.

What is CARF and when will HMRC start using it?

CARF stands for the Cryptoasset Reporting Framework, an OECD international standard. The UK began implementing it from January 2026. Cryptoasset service providers will be required to report customer transaction data to tax authorities, and HMRC expects to start receiving that data from 2027. It is broadly comparable to the Common Reporting Standard that already applies to offshore bank accounts.

How do I declare unpaid crypto tax to HMRC?

HMRC operates a disclosure facility on GOV.UK specifically for unpaid tax on cryptoassets. Voluntary disclosure before HMRC contacts you typically results in reduced penalties compared with being identified through an enquiry or, from 2027 onwards, through a CARF data match.

Is staking income subject to Income Tax in the UK?

HMRC's current position is that staking rewards are generally subject to Income Tax at the point of receipt, based on their sterling value at that time. There is no dedicated Self Assessment box for staking income; it is reported through existing Income Tax provisions. If you later sell the tokens received, any subsequent gain or loss is subject to CGT.

What is the Self Assessment deadline for crypto gains in 2025/26?

For the 2025 to 2026 tax year, you must declare cryptoasset income and gains above the relevant tax-free allowances and pay any tax owed by 31 January 2027. Missing this deadline triggers automatic late-filing penalties and interest on unpaid tax.