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Glossary

CARF: the Cryptoasset Reporting Framework for UK companies

An international reporting standard under which cryptoasset service providers collect and report customer and transaction details to tax authorities.

Education onlyUnited Kingdom and United States

Definition. The OECD based Cryptoasset Reporting Framework. In the UK, providers collect user and transaction details from 1 January 2026 and report them to HMRC.

United KingdomGo to United States

How it works

The Cryptoasset Reporting Framework is an international standard, developed through the OECD, for tax authorities to exchange information about cryptoasset transactions. In the UK, HMRC guidance says reporting cryptoasset service providers must collect details about their users and transactions from 1 January 2026. HMRC's page says first reports are due between 1 January and 31 May 2027. HMRC has changed the arrangements for first reports since it first published the guidance, so check its page for the current dates and method.

Why it matters for a company

A UK company that buys, sells or holds bitcoin with a UK provider will be asked for information. HMRC's guidance for users says a company must give its legal name, main address and company registration number, and some entities must also give details of the people who control them. HMRC says a user who does not give the information, or gives inaccurate information, can face a penalty of up to £300.

The practical point is consistency. The details the company gives the provider should match Companies House and its tax records, because HMRC will be able to compare what providers report with the company's own Corporation Tax return. A company that keeps clear transaction records in pounds, as HMRC already expects, will find any later questions easier to answer.

CARF reporting is done by providers, not by companies holding their own keys. A company that holds bitcoin in its own multisig wallet is not reporting under CARF for that wallet, but the transactions that pass through a provider, such as the purchase and any sale, will be reported.

Example only, fictional. A UK provider asks a company customer to confirm its registration number and the controlling persons. The company secretary answers from the Companies House record and the PSC register and keeps a copy of the response with the account opening file.

US domestic broker reporting runs through Form 1099-DA. See Form 1099-DA. This page does not describe whether or when the US will exchange information under CARF.

Common mistakes

Sources

Primary sources only. Each link was checked on 9 November 2026. Rules change, so confirm the current version with your adviser.

  1. HMRCCheck if you need to report cryptoasset data to HMRC (Cryptoasset Reporting Framework)
  2. HMRCInformation you need to give to UK cryptoasset service providers
  3. HMRCCRYPTO49000: Cryptoasset Reporting Framework
  4. HMRCIEIM8000050: Cryptoasset Reporting Framework, commencement
  5. IRSAbout Form 1099-DA, Digital Asset Proceeds From Broker Transactions
Education, not advice.

This is general information and education only. It is not financial, investment, tax, accounting, legal or regulatory advice, and it is not a recommendation to buy, sell or hold bitcoin or any other asset. It does not take account of your circumstances or those of your company. You must obtain your own official professional advice to confirm this information is correct before acting on it.

Rules change. This information is correct to our understanding at the last-reviewed date, but it may be incomplete or out of date, and official sources take precedence. Bitcoin is volatile. A company that buys it could lose some or all of the money it puts in.

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