UK tax agency steps up crypto scrutiny

TLDR

HMRC has significantly increased its monitoring of UK crypto investors, sending 81,000 warning letters and preparing new data-sharing rules that make hiding gains much harder.

1. HMRC has sent 81,000 nudge letters to crypto investors, a sharp rise that signals more proactive enforcement on unpaid tax.
2. UK rules treat many everyday crypto actions as taxable events, and future changes simplify DeFi tax but widen transparency.
3. From 20262028, exchange reporting and cross-border data sharing will give HMRC much clearer visibility into UK users crypto activity.

Deep Dive

1. Scale Of The Crackdown

Over the past 12 months, HMRC has sent 81,000 warning letters to UK crypto investors, up 25 percent from about 65,000 the year before and far above 27,714 in 202324. These letters, often called nudge letters, invite recipients to disclose unpaid tax before formal investigations start, and are targeted at those HMRC believes may have undeclared gains or income from crypto.

HMRC officials and tax advisers describe a growing expectation among tax authorities that crypto investment is heavily associated with tax evasion, which is driving this more aggressive outreach to UK-based holders and traders.

2. What Counts As Taxable Crypto Activity

Under UK rules, several common crypto actions can create a taxable event: selling crypto for pounds, swapping one token for another, spending crypto on goods or services, or gifting tokens. Income from lending, staking or similar activities can also be taxed separately.

The same report notes that UK residents are taxed on worldwide income and gains, including profits made on offshore exchanges, despite a common misconception that using overseas platforms avoids UK tax.

From April 2027, qualifying DeFi loans and automated market making will receive no gain, no loss treatment until there is a real disposal, which should simplify tax for around 700,000 individuals but does not remove tax entirely.

3. Data Sharing And Enforcement Trend

Crypto service providers in the UK will have to collect and report user information and transaction summaries for activity from 1 January to 31 December 2026, with reports due by 31 May 2027, according to the same analysis.

International exchanges will also share data on UK residents, with 52 jurisdictions participating in 2027 and another 15 in 2028, greatly expanding HMRCs ability to match blockchain activity to real-world taxpayers. This sits alongside wider UK enforcement, such as FCA raids on suspected illegal peer-to-peer crypto trading sites.

Conclusion

HMRCs rising letter campaign, clearer rules for DeFi, and upcoming global data sharing all point in the same direction: crypto is being folded into mainstream tax enforcement, not treated as a separate world. For UK users, the practical shift is from can HMRC see my crypto? toward how do I make sure my crypto activity is correctly reported before they do.