If you have received a letter from HMRC about your crypto activity, it can feel unsettling, even if you believe you have done nothing wrong.
Crypto nudge letters are part of HMRC’s data-led compliance campaigns. They are not formal investigations, but they do indicate that HMRC has access to information suggesting there may be something in your return worth reviewing.
In this article, we explain what a crypto nudge letter is, why you might receive one, and how to approach it carefully before responding.
Update: July 2026
HMRC has launched a new cryptoasset One-to-Many campaign running between July 2026 and March 2027, targeting individuals it believes may have underpaid Capital Gains Tax or Income Tax on cryptoassets.
As part of this campaign, HMRC may contact taxpayers by letter, email, text message and potentially through the HMRC app. Unlike previous campaigns, HMRC has also confirmed that agents will receive copies of letters sent to their clients.
If you've recently received a crypto letter from HMRC, the guidance in this article remains relevant. However, the latest campaign reinforces that crypto compliance continues to be an increasing area of HMRC focus.
Contents
- 1. What Is a Nudge Letter?
- 2. Why You Might Receive One
- 3. What To Do If You Receive a Nudge Letter
- 4. Before You Reply
- 5. Do You Have to Respond?
- 6. Are You Under Investigation?
- Conclusion
- Appendix 1: Example of January 2022 Nudge Letter
- Appendix 2: Example of August 2024 Nudge Letter
1. What Is a Nudge Letter?
A nudge letter is a communication from HMRC inviting you to review your tax affairs. It typically follows data received from third parties, such as crypto exchanges or overseas institutions, which suggests you hold or have held crypto assets.
These letters are part of HMRC’s “One to Many” campaigns. They are not formal enquiries, but they are targeted. HMRC uses data analysis to identify groups of taxpayers whose returns may not align with the information it holds.
HMRC has now undertaken three major crypto-focussed One-toMany campaigns.
- January 2022, primarily focused on undeclared disposals.
- August 2024, targeted both undeclared disposals and income.
- July 2026, targetting taxpayers believed to have underpaid income tax or capital gains tax on crypto as part of an extended campaign running until March 2027.
HMRC has confirmed that around 65,000 letters were issued in the August 2024 campaign, making it the largest crypto-focused compliance exercise to date. The scale of this exercise demonstrates that crypto is now firmly within routine compliance activity.
2. Why You Might Receive One
HMRC may issue a nudge letter following information received from crypto exchanges, earlier data-sharing agreements or wider compliance intelligence. As international reporting continues to expand through initiatives such as CARF, taxpayers should expect HMRC's visibility over crypto activity to increase further.
Common crypto-related triggers include:
- Selling or swapping crypto without reporting a gain
- Exchange-reported activity that does not match your tax return
- Receiving taxable income such as staking or mining rewards that were not declared
You do not need to be actively trading for HMRC to expect a declaration; even a single disposal can create a reporting requirement.
3. What To Do If You Receive a Nudge Letter
Receiving a nudge letter does not automatically mean you have made an error. However, it does mean HMRC expects you to review your position carefully.
The first step is to check your full crypto history and confirm whether all gains and income have been correctly reported. If you are unsure, or if you suspect something may have been missed, it is important to approach the situation methodically.
In many cases, uncertainty arises because records are incomplete or spread across multiple exchanges. If that is your position, you may first need to reconstruct your transaction history properly. Our guide on rebuilding messy crypto records explains how to approach that process.
4. Before You Reply
It is generally unwise to respond immediately without first understanding your full position.
A reply to HMRC should be based on a clear review of all relevant tax years, not just the year mentioned in the letter. Crypto disposals in earlier years may affect pool values and gain calculations in later years.
If there are gaps in your records, high transaction volumes, or activity across several exchanges, the figures generated by software should be reviewed carefully before being relied upon. The key issue is not the tool itself, but whether the data going into it is complete and properly categorised.
The way you respond can influence how HMRC views your behaviour. Penalties depend heavily on whether reasonable care was taken and whether any disclosure is voluntary or prompted. We explain the behavioural categories and their impact on penalties in our article on HMRC penalties for crypto tax errors.
5. Do You Have to Respond?
A nudge letter is not a formal enquiry, and there is not always a strict legal obligation to respond. However, ignoring it where there is a genuine discrepancy increases the likelihood of a formal enquiry being opened later.
If HMRC opens a formal enquiry and identifies undeclared gains or income, penalties may be higher than if you had reviewed and corrected the position earlier.
Even where you believe your return is correct, it is important to read the letter carefully. HMRC’s guidance has varied between campaigns. For example, the January 2022 crypto nudge letter indicated that no response was required if you were satisfied your return was complete, whereas the August 2024 crypto nudge letter suggested that HMRC should be contacted if you believed everything was in order.
6. Are You Under Investigation?
No. A nudge letter is not the same as a formal investigation.
However, it is an opportunity for HMRC to prompt a review before deciding whether further action is necessary. If no action is taken and HMRC continues to believe there is a discrepancy, it may open a formal enquiry.
We discuss the broader risks of leaving crypto activity undeclared in our article on the consequences of not reporting crypto to HMRC.
Conclusion
HMRC crypto nudge letters are designed to prompt a review, not to accuse. However, they should not be ignored.
The launch of HMRC's latest One-to-Many crypto campaign in 2026 reinforces that crypto compliance remains a significant area of focus for HMRC. If you've recently received a letter, email or text message about your cryptoassets, it's sensible to review your position carefully before responding.
If you are confident that your returns are complete and your records are accurate, you may simply need to document your review and follow the instructions in the letter. If you are unsure whether everything has been declared, the sensible approach is to reconstruct your position fully before replying.
Where there are multiple tax years involved, incomplete records, or significant values at stake, a more detailed review may be appropriate before responding. The way a nudge letter is handled can influence how HMRC views your behaviour and can affect penalties if adjustments are required.
If you are uncertain about your disclosures or how to respond, it is usually better to have your position reviewed before replying to HMRC.
Need help responding to an HMRC crypto letter?
If your records are incomplete or you're unsure whether everything has been reported correctly, our guide explains how we support clients from initial review through to responding to HMRC.
Read: How we help clients respond to HMRC crypto nudge letters.
FAQs
A nudge letter is a communication from HMRC inviting you to review your tax affairs. It is not a formal investigation, but it usually indicates that HMRC holds data suggesting your return may not align with information received from third parties, such as crypto exchanges.
HMRC receives information from exchanges and overseas tax authorities. You may receive a nudge letter if your tax return appears not to align with that data, or if a return was expected but not filed.
There is not always a legal obligation to reply, particularly if you are satisfied your return is complete. However, if you are unsure whether everything has been declared, it is important to review your position carefully before deciding whether to respond.
Before responding, you should review your full crypto position to confirm whether all gains and income have been correctly reported. If adjustments are required, it is sensible to seek advice on the most appropriate way to disclose them to HMRC.
Not usually. Nudge letters are part of HMRC’s One to Many campaigns and are intended to prompt a review before a formal enquiry is considered. However, if HMRC later opens an enquiry and identifies undeclared income or gains, penalties may be higher than if the issue had been addressed earlier.
Yes. The nudge letter issued by HMRC in August 2024 specifically mentioned undeclared income from crypto as well as undeclared gains on disposal.
HMRC has now undertaken three major crypto-focused One-to-Many campaigns. The first was in January 2022 targeting undeclared disposals, the second in August 2024 targeting undeclared crypto income and gains, and the latest campaign began in July 2026. The 2026 campaign runs until March 2027 and HMRC has said it may contact taxpayers by letter, email, text message and potentially through the HMRC app.
Appendix 1: Example of January 2022 HMRC Crypto Nudge Letter
This is an example of the crypto nudge letter issued by HMRC as part of its "One to Many" campaigns around early 2022. If you’ve received something similar, review your records carefully before responding.
Appendix 2: Example of August 2024 HMRC Crypto Nudge Letter
This is an example of the crypto nudge letter issued by HMRC around August 2024. Unlike the 2022 nudge letter, this letter targets both undeclared disposals and undeclared income.
