・7 min read・Crypto
Received an HMRC crypto nudge letter? What to do next
Received an HMRC crypto nudge or warning letter? Start with the practical steps to check your records and work out what to do before you reply.
Received an HMRC crypto nudge letter or crypto warning letter? The BBC reported that HMRC had issued more than 81,000 crypto-tax warnings as it increases its focus on compliance.
Receiving a letter can be unsettling, especially if your crypto activity spans several exchanges and wallets. A crypto nudge letter may ask you to check whether income or gains have been reported correctly, correct your position where needed, and respond by a stated date. Read your individual letter closely.
Start by checking that the letter is genuine through HMRC’s official guidance. Then read exactly what it asks you to do, note any deadline in the letter, and reconstruct your crypto history across every exchange and wallet. Exchange reports do not give you a tax calculation or track pooled costs across every wallet and platform. CoinTracker can turn that fragmented history into a calculation of your UK gains, losses, and income before you respond.
Quick answer: what to do after an HMRC crypto notification letter
Start with these five steps, in order. They will help you check the letter, establish what HMRC has asked, and identify the appropriate next route:
- Confirm that the letter is genuine using HMRC’s official contact checker.
- Read the letter closely. Keep a copy, then record exactly what it asks you to do, how HMRC tells you to respond, and any deadline stated in it.
- Assess your potential tax position by building one complete crypto record across exchanges, wallets, bank payments, and earlier returns. Use CoinTracker to consolidate activity from your exchanges and wallets before comparing it with earlier returns.
- Compare that record with your previous tax returns and calculations.
- Follow the letter’s instructions and respond based on what your records show. If you identify an error, correct the return or make a disclosure where appropriate. If your records support no unpaid tax, have that evidence ready and explain your position if the letter asks you to.
How to check an HMRC crypto letter before responding
Check the contact method through HMRC
HMRC says it may contact cryptoasset users by letter, email, or text. A genuine contact may direct you to GOV.UK guidance, but open GOV.UK yourself rather than relying on a link, QR code, phone number, or email address in an unexpected message. Use HMRC’s current crypto contact guidance to check it before you respond.
Fraudsters can imitate an HMRC crypto email or text. Report suspicious HMRC emails and texts: forward a suspicious email to [email protected] or a suspicious text to 60599, then do not engage.
Build a complete crypto record before you reply
Read the confirmed letter closely. Note exactly what it asks you to do, how HMRC tells you to respond, and any deadline stated in it. Then build the complete crypto history you need to answer that request.
HMRC requires you to keep records of your crypto transactions. Its cryptoasset recordkeeping guidance explains why an exchange report can help but cannot replace your own calculation or Section 104 pooled-cost record.
Gather the evidence across exchanges, wallets, and bank records
Gather the accounts and wallets you controlled for the tax years you need to review, then connect each platform record to the wider history.
| Records to gather | Why it matters |
|---|---|
| Exchange histories and exports | Establish activity recorded by each platform |
| Wallet addresses and transaction history | Connect same-owner movements and off-exchange activity |
| Bank or payment evidence | Support the acquisition, disposal, and cash-flow timeline |
| Dates, quantities, and sterling values | Support a review of figures reported to HMRC |
| Earlier returns and working papers | Compare the reconstructed history with what you previously reported |
Build the working record in CoinTracker
If you are consolidating activity across exchanges and wallets, CoinTracker brings your crypto activity into one place, calculates your UK crypto gains, losses, and income, and prepares a UK Self Assessment Summary. The report maps core crypto figures to SA108 Cryptoassets boxes 13.1 to 13.5 and SA100 box 17.
Get started with CoinTracker to turn those account and wallet records into one working record for your UK crypto review.
Reconcile the history with prior returns
Compare the gains, losses, and income in your completed record with the figures and calculations you reported on each relevant tax return. If the numbers differ, determine whether the original return needs correcting or whether your completed record explains the difference.
What your records may show
If your records support no unpaid tax
If your records support no unpaid tax, respond as the letter asks. Explain why you believe the right tax was paid, and provide the calculation and records the letter requests.
If you find a possible error in an open return
If your completed record shows an error in a Self Assessment return that is still within its amendment window, amend your tax return. HMRC allows an amendment within 12 months of the filing deadline. Confirm the tax year and amendment window first.
If the amendment window has closed, follow the route in the letter where it gives one. If it does not, use HMRC’s current guidance for the tax year and error you identified.
If you cannot yet establish the position
If you are waiting for older exchange records or need more time to reconstruct a complex history, respond through the route in the letter before its deadline. Tell HMRC which records are outstanding and that you are obtaining them.
Ask each exchange for its full transaction history, collect wallet and bank records, and finish the calculation. Your final position should be supported by the completed record, not only by an explanation that records are still outstanding.
If you identify unpaid crypto tax and amendment is not available, or the letter directs you there, review HMRC’s Cryptoasset Disclosure Service. It requires a calculation and is not an automatic response to every HMRC crypto letter.
What crypto activity should I review?
Review every activity that may change your Capital Gains Tax or Income Tax calculation. This includes more than sales for pounds:
- Sales for pounds, crypto-to-crypto exchanges, crypto spending, and relevant gifts can create Capital Gains Tax questions. See HMRC’s guidance on selling cryptoassets.
- Crypto received from mining, staking, lending, employment, or services can create Income Tax questions. See HMRC’s guidance on receiving cryptoassets.
- DeFi and liquidity-pool activity can involve a disposal, a reward or other amount you receive from the arrangement, or both. Review each transaction and amount received before deciding how it affects your calculation.
HMRC says an amount received from a DeFi arrangement can be income or capital depending on the arrangement. Its liquidity-provider example shows why each transaction needs its own review.
Organize crypto records for an HMRC response with CoinTracker
For a broader explanation of UK rules, read our UK crypto tax guide. When you are ready to prepare your own UK crypto figures, get started with CoinTracker.
Disclaimer: This post is informational only and is not intended as tax advice. For tax advice, please consult a tax professional.
FAQ
What is an HMRC crypto nudge letter?
An HMRC crypto nudge letter is a compliance prompt about your crypto tax reporting. It asks you to check whether your crypto income or gains have been reported correctly and, where necessary, correct them. If you believe the right tax was paid, be ready to explain your calculation and provide supporting records if the letter asks.
What should I do if I receive an HMRC crypto warning letter?
Confirm that the letter is genuine. Note what it asks you to do and any deadline, then compare the concern in the letter with your filed returns and existing crypto records. If you do not have a complete record across your accounts and wallets, build one before deciding whether to correct a return, disclose unpaid tax, or explain why your reporting is correct.
Does an HMRC crypto letter mean I owe tax or face an investigation?
Not automatically. It means HMRC has seen crypto activity or other information that it wants you to check against your tax reporting. You may need to correct or disclose something, or explain why your return is already correct. A nudge letter is not the same as a formal compliance check. If HMRC opens one, it will write to explain what it wants to check and why.
How long do I have to respond to an HMRC crypto letter?
Use the deadline in the verified letter. HMRC has not published one generic response period for every crypto notice.
Can I amend a Self Assessment return for crypto?
Yes. You can amend a Self Assessment return within 12 months of its filing deadline. After that, write to HMRC to report income you did not include in the return. If you think you overpaid tax, you can claim overpayment relief up to 4 years after the end of the relevant tax year.
Does HMRC know about my crypto?
Potentially. HMRC says information you give to cryptoasset service providers can be used to link your crypto activity to your tax record. From 2026, providers will collect and report data under CARF, with the first reports due to HMRC in 2027.