UK Crypto Tax Crackdown: Warning Letters Soar as Bull Market Gains Come Under Scrutiny

HMRC's crackdown on crypto tax evasion has intensified in the UK, with over 81,000 warning letters sent to suspected unpaid crypto holders in 2025/26. This total is nearly triple the number of letters issued in 2024 (27,714). The surge reflects gains many holders made during the 2022-2025 bull market run.

According to HMRC data, most outstanding crypto tax liabilities are attributed to gains realized during this period. Under current rules, selling, gifting, or swapping cryptocurrencies can trigger a capital gains tax bill. Many traders remain unaware that these everyday actions count as taxable events.

Penalties for unpaid crypto tax can reach 100% of the amount owed, plus interest. HMRC expects to gain new enforcement powers next year targeting offshore platforms, which would force them to share customer data directly with the tax authority. Officials estimate this could raise up to £315 million in revenue by 2030.

Tension between UK banks and crypto investors continues to build, with a group of MPs raising concerns about ongoing account restrictions facing digital asset businesses. HMRC's ramped-up letters and new offshore powers signal a tougher environment ahead for UK crypto users.