# CARF: what UK crypto exchanges report to HMRC from 2026

CARF (Cryptoasset Reporting Framework) requires UK crypto service providers to report customer transaction data to HMRC from 2026. First reports cover calendar year 2026 and are due by May 2027. You must still file your own Self Assessment — CARF helps HMRC check what you declare.

## Key facts
- CARF is based on OECD international standards adopted by the UK.
- Providers collect identity and transaction data from 1 January 2026.
- First reports to HMRC are for the 2026 calendar year.
- CARF does not calculate your tax — you still keep records and report gains.
- Undeclared crypto tax remains your responsibility.

## What CARF is

The Cryptoasset Reporting Framework is an international system for sharing information about crypto transactions between tax authorities. The UK implemented it through the Finance (No. 2) Act 2024. HMRC published implementation guidance for service providers.
## What providers must report

In-scope UK cryptoasset service providers must collect customer details (including tax residence and National Insurance number where applicable) and report transaction records — including types of transactions and sterling values — to HMRC annually.
## What you should do

Keep your own transaction records as before. When you complete Self Assessment, declare crypto gains and income accurately. If you have undeclared tax from earlier years, HMRC operates a disclosure route for cryptoassets on gov.uk.

## FAQs
### Will HMRC know automatically if I sell crypto?

From 2027 onwards, HMRC will receive reports from UK providers about 2026 activity. You remain legally required to report taxable gains and income regardless.

## Sources

- [HMRC — Cryptoasset Reporting Framework](https://www.gov.uk/government/publications/cryptoassets-reporting-framework)
- [HMRC — Information for individuals](https://www.gov.uk/guidance/information-you-need-to-give-to-uk-cryptoasset-service-providers)

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— Digital Assets UK (https://digital-assets.co.uk/tax/carf-reporting-2026/), reviewed 2026-06-23. Source: https://www.gov.uk/government/publications/cryptoassets-reporting-framework