UK’s 81,000 crypto warnings offer a glimpse of 2027 tax crackdown

Britain’s tax authority sent more than 81,000 warning letters to crypto investors over the past year. This highlights a sharp rise in scrutiny of digital asset holdings. Meanwhile, a much bigger change is coming in 2027, when the UK and dozens of other jurisdictions are expected to begin automatically sharing crypto account information under a new global tax reporting framework.

The OECD’s Cryptoasset Reporting Framework (CARF) will come into effect in 2027 in the UK. It is one of 46 countries that committed, according to the OECD list of commitments issued in June. It is expected that 29 more countries will join in 2028, while the United States will become part of the framework in 2029. The UK tax authority, HM Revenue and Customs (HMRC), provides insights into how this enforcement framework might play out.

The 81,000 figure and how fast it climbed

Around 81,000 letters were uncovered via a Freedom of Information request made by the accounting firm UHY Hacker Young and published on August 20. The number of nudge letters sent out by HMRC has increased by 25% from about 65,000 letters sent out the previous year. The total number of letters in 2023-24 is merely 27,714, which signifies a nearly 300% increase in two years.

Nudge letters do not represent official investigations. They offer taxpayers the opportunity to report the unpaid tax before HMRC pursues the matter. UHY Hacker Young reported that the penalties for voluntary disclosures can be limited to 30% of the total amount of unpaid tax, as opposed to 70% to 100% of it once HMRC has intervened in the situation.

According to Neela Chauhan, who is part of the firm, many holders of cryptocurrencies are young, inexperienced with tax authorities, and believe that their actions are not noticed. She said:

“There is the expectation amongst tax authorities that cryptocurrency investment is rife with tax evasion”

Why offshore exchanges stop being a shield

HMRC can receive information from UK platforms now, and by 2027, it will be able to access more information.

Chauhan said UHY expects 52 jurisdictions to provide HMRC with data on UK residents in 2027, including the Channel Islands, Cayman Islands, Ireland and Liechtenstein. Another 15, including Singapore, Switzerland and Gibraltar, are expected to join in 2028.

The records can be quite large in scope. In the UK, they would include transaction details with identifying information such as names, addresses and National Insurance numbers. According to Chauhan, the moment HMRC acquires the data, investigations will be “like shooting fish in a barrel.”

The same trend is happening throughout Europe. The EU’s DAC8 directive, which draws inspiration from the OECD framework, came into force as of January 1, 2026. Member states are expected to exchange information on crypto-assets for the reporting year 2026 by September 30, 2027.

In practice, this means that the use of a platform in one of the participating jurisdictions will provide less and less comfort from the scrutiny of local tax authorities.

What HMRC counts as a taxable event

Part of the compliance problem is that crypto tax rules are easy to misunderstand. Selling crypto for pounds is an obvious taxable disposal, but swapping one token for another can also qualify. So can spending crypto or giving it away. Lending and staking income may fall under separate income-tax rules.

Another common mistake, Chauhan said, is assuming an overseas account falls outside UK tax rules. UK residents are generally taxed on worldwide gains, meaning profits made through foreign platforms can still be reportable at home.

Cryptopolitan reported in January that HMRC had framed its crypto data push as part of an effort to recover about £300 million in tax, with the capital gains tax-free allowance set at £3,000.

The April 2027 DeFi change

At the same time, the UK is changing how some decentralized finance activity is taxed. From April 2027, qualifying crypto lending and automated market-making arrangements will receive no-gain, no-loss treatment until an actual economic disposal occurs. The change defers tax rather than eliminating it.

UHY Hacker Young estimates the revised treatment of crypto lending and liquidity pools could affect about 700,000 people.

For the wider market, the direction is clear. Governments are not only refining crypto tax rules; they are connecting their reporting systems across borders. As those exchanges begin, the long-standing assumption that tax authorities cannot see offshore crypto activity becomes much harder to sustain.

UK crypto-tax enforcement is accelerating

The tax authority recovered more than £8.3 million through settlements in 2024–25 and 2025–26, while crypto-related warning letters climbed from 8,329 in 2021–22 to more than 81,000 in 2025–26. The settlement figures should not be interpreted as HMRC’s total crypto-tax revenue.

*The available FOI series reports no crypto CGT nudge letters for 2022–23. The warning-letter figures for 2021–22, 2023–24 and 2024–25 come from FOI data obtained by BrokerChooser/UHY Hacker Young. The interesting divergence is that settlement collections rose while the number of settlements fell:

280 settlements → 222 settlements
£3.5m → £4.8m recovered

That means the average recovery per case increased by approximately 73%, from £12,500 to £21,600.

The next major data point is 2027, when CARF reporting starts feeding HMRC standardized crypto transaction data. HMRC says UK reporting cryptoasset service providers began collecting the required information from January 1, 2026, with the first reporting period ending December 31, 2026.

What happens if you pay late?

Receiving a nudge letter isn’t itself a 15% penalty. The taxpayer generally has an opportunity to correct their position before HMRC moves into formal enforcement.