- CARF now requires crypto platforms to collect and report detailed user and transaction data
- HMRC will receive its first reports in 2027, covering activity from 2026
- Incorrect information or unpaid tax can lead to heavy penalties
Crypto is entering a new phase of transparency. Under the OECD’s Cryptoasset Reporting Framework, or CARF, crypto-asset service providers across the UK and more than 40 other countries are now required to collect and report detailed user and transaction data. The rules officially took effect on January 1, 2026, marking a major shift in how governments track crypto activity for tax purposes.
What CARF Is Designed to Do
The goal of CARF is straightforward: prevent crypto assets from becoming a blind spot for tax authorities. By creating a standardized, global reporting system, the framework enables automatic information sharing between participating countries. That means crypto transactions are increasingly treated like traditional financial activity, at least from a reporting standpoint.
Under updated guidance first issued last May, anyone buying, selling, transferring, or exchanging crypto must provide accurate identifying information to the platforms they use. For individuals, this includes name, date of birth, address, and tax identification number where applicable. Businesses and other entities must submit full corporate and tax details.
What Crypto Platforms Must Collect
Crypto exchanges, wallet providers, and other service platforms are now required to track far more than just balances. They must record identity information, tax residency, and complete transaction histories, including gains and losses. These obligations apply to both UK-based users and international customers using UK-registered services.
The scope is broad, and it effectively eliminates anonymity at the service-provider level, even if the underlying blockchain remains pseudonymous.
When Reporting Starts and What Happens If You Don’t Comply
The first CARF reports will be submitted to HMRC by May 31, 2027, covering all crypto activity from the 2026 tax year onward. That information will also be shared with other participating tax authorities, increasing the likelihood that undeclared crypto income is detected across borders.
For UK users, providing incorrect or missing information can result in fines of up to £300. Failing to pay tax owed on crypto gains can trigger penalties of up to 100% of the unpaid tax, plus interest. In offshore or international cases, penalties can be even more severe.
