$457 Billion in Onchain Taxable Activity, 14% Covered by CARF

Blockchain analytics firm Chainalysis estimates there was at least $457 billion in onchain taxable crypto activity in 2025 — and that the OECD's Crypto-Asset Reporting Framework (CARF) covered only about 14% of it.

The finding, published in a report on Thursday, quantifies a problem tax authorities have suspected since crypto moved mainstream: the sector's taxable footprint is growing faster than the reporting infrastructure built to track it.

How the Gap Arises

CARF requires crypto-asset service providers — primarily exchanges and custodians — to collect and exchange information about their users' transactions with tax authorities across jurisdictions. But a large share of activity now happens where CARF does not reach: decentralized protocols with no service provider to act as reporting intermediary, self-custodied wallets interacting peer-to-peer, and venues operating from jurisdictions that have not committed to the framework's first exchanges.

Chainalysis's estimate covers realized capital gains, income events and other taxable onchain activity. Even taken as a floor — the firm says "at least" $457 billion — the uncovered 86% represents tens of billions in potential tax base that governments currently cannot see through mandated channels alone.

Authorities Are Closing In From Other Directions

Tax agencies are increasingly using analytics and disclosure data to bridge the gap. In the UK, government figures released this week showed about 17,600 people reported a combined $1.9 billion in crypto gains for the 2024–25 tax year — including 240 crypto millionaires, each declaring more than $1.4 million.

The disclosure numbers are small relative to Chainalysis's activity estimate, which is precisely the point: the spread between what is declared and what occurs onchain is the gap regulators are trying to close, either by extending CARF's scope in later phases or by leaning on blockchain analytics to reconstruct undeclared activity.

What Comes Next

Further CARF signatories are expected to activate exchanges of information in phases through 2027, covering 2026 data for early adopters. Whether the framework expands to cover DeFi and self-custody — the largest uncovered segments — remains an open policy question, and one with direct revenue implications for finance ministries already factoring crypto into budget planning.