Two major changes are reshaping crypto tax reporting in the UK. HMRC is set to receive transaction data directly from exchanges, while also asking for more detail from you through the self-assessment return. This “double disclosure” model will make it easier to match your return with real trading activity. Over recent years, we have seen HMRC take a more structured and data-driven approach to crypto compliance, and these developments are a continuation of that trend.
Contents
- 1. What’s changing for crypto platforms
- 2. Which exchanges and crypto service providers will be affected?
- 3. What’s changing for your tax return
- 4. Our View
- FAQs
- References
1. What’s changing for crypto platforms
From 1 January 2026, cryptoasset service providers in the UK must start collecting and reporting user data to HMRC.
This follows the UK’s adoption of the OECD Crypto-Asset Reporting Framework (CARF). Platforms will be required to report:
- User identity details (name, address, date of birth, National Insurance number or taxpayer ID)
- Transaction data, including buys, sells, exchanges and airdrops
- GBP valuations at the time of each transaction
If you invest through an entity, such as a limited company, then the platform will be required to collect:
- Legal business name
- Main business address
- Company registration number, for UK limited companies
The first reports will be due by 31 May 2027, covering all activity in the 2026 calendar year. Platforms that fail to comply may face fines of £300 per user or more. Similarly, investors that refuse to provide the information, or provide inaccurate information, could receive a penalty of £300.
2. Which exchanges and crypto service providers will be affected?
One of the most common questions we are asked is: “Which crypto exchanges report to HMRC?” These reporting requirements begin to provide answers to that question. Both UK-based and non-UK platforms may be affected, although in different ways.
- UK platforms will be required to report user information directly to HMRC under domestic CARF implementation rules.
- Non-UK platforms may also trigger reporting to HMRC if they operate in a country that has adopted CARF and you are a UK resident.
HMRC has confirmed that information shared with foreign tax authorities under CARF will be passed back to the UK where relevant. This means UK users of overseas exchanges could still be visible to HMRC, even if the platform is not UK-based.
For more information, including a full list of participating jurisdictions, check out our Definitive Guide to CARF for UK Investors.
3. What’s changing for your tax return
From the 2024/25 tax year, the self-assessment tax return includes a dedicated section for cryptoassets.
You will need to report:
- Number of crypto disposals
- Total disposal proceeds
- Total allowable costs (such as acquisition costs and allowable expenses/fees)
- Disclose total gains and total losses separately
- Indicate whether any claims or elections have been made (such as a negligible value claim).
Previously, crypto gains were entered under “other capital gains”. In practice, this means the figures you disclose will be easier for HMRC to compare against platform-reported transaction data.
4. Our View
These developments appear designed to operate in tandem, with platform-level reporting creating visibility over transactions and enhanced tax return disclosures requiring more structured reporting from taxpayers.
Taken together, they create what we have described as a “double disclosure” model.
- Data from crypto platforms will show what transactions took place. This creates an expectation within HMRC systems as to what taxpayers should be reporting.
- Data from your tax return will show what you’ve actually declared in relation to your crypto activity.
This will make it easier for HMRC to reconcile reported figures with platform-level data and identify discrepancies. For example:
A crypto platform reports that you sold tokens worth £100,000 in 2024/25, but box 13.2 of your tax return only shows proceeds £20,000. This could indicate that you have failed to declare £80,000 of disposals.
HMRC will also be able to identify situations where record keeping is incomplete or where the reporting rules have been misunderstood. For example:
You sell Bitcoin in five tranches but report a single disposal in box 13.1, assuming you only need to disclose one disposal because they all related to the same token type i.e. Bitcoin. However, the crypto platform correctly reports five disposals. Even if your total disposal proceeds and gain are accurate, this mismatch may flag your record keeping as inadequate.
In our experience, most discrepancies in crypto reporting arise from incomplete records or misunderstanding of disposal rules. They are rarely deliberate, but they can still create risk where figures do not clearly align.
Depending on the scale of the discrepancy, HMRC may issue a crypto nudge letter, open an enquiry, or raise a formal challenge.
It would be reasonable to expect increased compliance activity from 2027 onwards, when returns begin to reflect years covered by CARF reporting.
As reporting becomes more structured, taxpayers will need to be confident that their disclosed figures can be clearly supported and reconciled to underlying transaction data. For many investors, that requires more than simply checking totals, particularly where there have been multiple platforms or more complex crypto activity.
If you are unsure whether your reporting approach would withstand this level of comparison, our crypto tax support packages are designed to ensure your records and reporting are robust and fully supported.
FAQs
HMRC will receive detailed transaction data from UK-based crypto platforms, including your name, address, date of birth, and National Insurance number. The reports will also include crypto transaction data such as buys, sells, swaps, and airdrops, along with the GBP value of each transaction at the time it took place. This reporting applies from the 2026 calendar year, with the first reports due by 31 May 2027.
UK-based crypto platforms will be required to report user data directly to HMRC. Non-UK platforms may also trigger reporting if they operate in a country that has adopted the CARF framework and you are a UK tax resident. Many major exchanges operate across jurisdictions that have committed to CARF implementation, which increases the likelihood that UK resident users will fall within reporting scope.
From the 2024/25 tax year onwards, the UK self-assessment return includes a dedicated crypto section. You will need to report the number of disposals, total proceeds, total allowable costs, total gains and total losses. You will also need to indicate whether you have made any claims, such as a negligible value claim. This replaces the previous approach of grouping crypto gains under other capital gains.
If you refuse to provide the required identity details or submit false information, you could face a penalty of £300. Crypto platforms are under a legal obligation to collect accurate personal data under the CARF rules. Where identity details are incomplete or inaccurate, this may increase the likelihood of further enquiries once reporting begins.
