HMRC has said it will start receiving customer data directly from cryptoasset service providers ,as part of a new international reporting standard already being phased in. The moves comes after 240 people declared more than £1m ($1.35m) each in cryptoasset gains in the 2024-25 tax year.
According to the figures, published as part of HMRC’s annual Capital Gains Tax statistics, 17,600 individuals made taxable disposals that year, reporting combined gains of £1.38 billion ($1.86 billion) on disposal proceeds of £13.8 billion ($18.68 billion). Within that group, 240 people accounted for £717m ($971m) in gains between them, an average of just under £3m ($4.06m) each. It is the first time HMRC has broken out this data, a move made possible by a dedicated cryptoasset section added to the Self Assessment return.
OECD international standards
HMRC’s new policy relates to the Cryptoasset Reporting Framework (CARF), an international standard developed by the OECD that the UK began implementing in January 2026. Under CARF, cryptoasset service providers including exchanges, custodians and similar platforms, will be required to collect and report customer information to tax authorities. HMRC confirmed it will start receiving this data from 2027.
This new obligation comes with a real enforcement mechanism attached. Providers that fail to comply face penalties of up to £300 ($406) per user. Unlike a flat corporate fine, a per-user penalty scales directly with the size of a platform’s customer base, which means the cost of onboarding, data collection, and reporting errors could be substantial for larger firms.
For compliance functions, this has practical implications beyond the tax desk. CARF reporting will require robust customer identification and data-collection processes. This will overlap with existing KYC and AML infrastructure, even though CARF itself is a tax transparency rather than an AML measure. Firms that haven’t yet mapped their CARF obligations against their existing client onboarding and data governance frameworks have a relatively short runway before the 2027 reporting deadline.
“We want to make it as easy as possible for people to understand and meet their tax obligations when it comes to cryptoassets,” John-Paul Marks, permanent secretary and chief executive, HMRC, said. “As new international reporting rules come into force, it’s more important than ever for people to check they are paying any tax owed.”
The substantive regulatory development is the shift from self-reported to third-party-reported crypto data. For compliance officers, the near-term task isn’t interpreting HMRC’s statistics, it’s assessing readiness for a reporting obligation that starts biting in under 18 months, with penalties that scale with customer numbers rather than being fixed.