HMRC Self Assessment reminder for crypto users
Summary: Tax reminder (9 January 2024): HMRC reminded cryptoasset users to check whether gains or income require a Self Assessment tax return — including swaps, staking rewards and airdrops. Keep exchange CSVs and use our tax hub; this is not HMRC advice. See the gov.uk news item for the official wording.
Who might need to file
You may need Self Assessment if total taxable gains exceed the annual exempt amount, or if proceeds exceed £50,000 in a tax year (even if gains are below the allowance). Crypto-to-crypto swaps count as disposals.
Records to keep
Download CSV history from every exchange and DeFi platform you used. Note wallet addresses, dates, amounts in sterling, and fees. Section 104 pooling applies — our tax hub explains calculation.
What changed since 2024
CARF data collection began January 2026, increasing HMRC visibility. Undeclared earlier years may still be corrected through disclosure — waiting increases penalty risk.
Frequently asked questions
I only bought and held — do I need to file? +
Buying with fiat and holding usually creates no CGT event until you dispose. Check if you had any swaps, staking income or airdrops.
What is the deadline? +
Online Self Assessment for 2025/26 is due 31 January 2027. Register in time if you are new to Self Assessment.