Reporting cryptoasset user and transaction data

If you provide cryptoasset services in the UK, you must collect data and report it to HMRC.

This is because of rules called the Cryptoasset Reporting Framework (CARF).

You can subscribe to get email updates about Cryptoasset Reporting Framework guidance.

You need to collect details of all of your users, but you only need to report on users who are tax resident in the UK or another country that is signed up to CARF rules.

You need to report these users’ details and a summary of their transactions.

If you have no information to report in a year, you do not need to submit a report.

Your data must be submitted in XML file format.

Each file can be up to 250MB — you can split your data into more than one file, if needed. It must not be a compressed zip file.

To create your XML file, you must use the:

You’ll need to upload your report to our online service. It’s not live yet — we’ll update the guidance when it is.

You need to submit your first report by 31 May 2027, giving details for 1 January 2026 to 31 December 2026.

In future years you’ll also need to submit a report by 31 May, giving details for the previous calendar year.

If you do not follow the rules, we may charge you a penalty of up to £300 per user.

You can find detailed information about the Cryptoasset Reporting Framework: