Why did HMRC send you a crypto tax letter? Here are the most common triggers for HMRC crypto investigations in 2025.
Intro
Many UK crypto traders have started receiving letters from HMRC about undeclared crypto activity. But what triggers these investigations?
Common Triggers
- Exchange-reported data doesn’t match your return
- HMRC gets data directly from exchanges. If your report doesn’t line up, red flag.
- Sudden large transfers
- Moving £50k+ without reporting can get flagged.
- NFT & DeFi activity
- Buying/selling NFTs, liquidity pools, and yield farming all count. If undeclared, HMRC notices.
- Social media signals
- Believe it or not, HMRC does check Twitter, Discord, and Reddit for traders bragging about gains.
What To Do If You Get a Letter
- Don’t ignore it — penalties get worse.
- Gather your records — CSVs, wallets, transfers.
- Respond professionally — with a clear, accurate tax report.
Final Thoughts
Getting a letter isn’t the end of the world — if you handle it correctly.
👉 TaxAnon specialises in preparing clean, HMRC-compliant reports fast, so you can respond with confidence.