Chainalysis Says Crypto Tax Non-Compliance May Top 90%…

Crypto tax non-compliance may exceed 90% in some markets, according to research highlighted by Chainalysis, as France prepares for a reporting regime that will give authorities substantially more information about cryptocurrency transactions from 2027. The figure does not represent an estimate of French non-compliance.Instead, Chainalysis cited evidence from Sweden, where the country's tax authority previously found that more than 90% of reviewed crypto users had failed to correctly report their activity. France nevertheless presents a significant enforcement test. Chainalysis estimates the country generated approximately $9.4 billion of potentially taxable onchain crypto activity during 2025, ranking 13th among markets included in its study. That consisted of roughly $2.5 billion in realized gains, $1.7 billion of crypto-related income and $5.2 billion of payments.

France Faces a $9.4 Billion Reporting Challenge

Chainalysis estimates potentially taxable crypto activity reached at least $457 billion globally in 2025 across six blockchains: Bitcoin, Ethereum, Solana, Tron, BNB Smart Chain and Base. The European Union collectively accounted for approximately $125.1 billion, while the United States led individual countries with $112.6 billion. France's $9.4 billion provides a striking comparison with existing tax declarations.Approximately 24,000 French taxpayers declared a combined €368 million of net cryptocurrency capital gains for the 2024 tax year. But the two numbers cannot be treated as evidence that billions of dollars of French taxes went unpaid. They cover different years and measure different things.The €368 million represents declared net capital gains, while Chainalysis' $9.4 billion estimate includes income, realized gains and payments that can receive different tax treatment. Chainalysis itself describes the figure as "potentially taxable activity," not unpaid tax revenue. Its methodology may also underestimate some activity because transactions conducted internally on centralized exchanges are not always visible on public blockchains.

DAC8 Gives Tax Authorities New Visibility in 2027

The enforcement environment is now changing. The EU's DAC8 tax-transparency rules took effect on January 1, 2026, requiring reporting crypto-asset service providers to begin collecting transaction and identification data on EU-resident customers.Providers must collect information including tax residence and identifying details while reporting aggregated transaction values and counts across covered crypto assets. The rules encompass crypto-to-fiat disposals, crypto-to-crypto transactions and transfers involving external addresses. That means transfers to self-custody wallets can appear in provider reports, although DAC8 does not give exchanges continuous visibility into subsequent activity conducted entirely through private wallets.The first reporting year is 2026. Providers will submit that information during 2027, with EU tax authorities required to exchange the first datasets by September 30, 2027. France has already incorporated the CARF/DAC8 reporting framework into its domestic tax infrastructure.The OECD's Crypto-Asset Reporting Framework extends similar information-sharing beyond the European Union, with most participating jurisdictions planning their first exchanges in 2027. Significant blind spots will remain.Chainalysis estimates only around 14% of the potentially taxable onchain activity identified in its study falls within the practical reporting reach of CARF. The remaining 86% includes activity involving areas such as decentralized exchanges, peer-to-peer transfers, payments and onchain income where centralized intermediaries may not possess enough information to automatically identify taxpayers.That does not make the activity invisible. Tax authorities can combine exchange records with blockchain analytics, audits and information obtained from other jurisdictions to reconstruct transactions. What changes in 2027 is the amount of identity-linked information arriving automatically. For French crypto investors, that could significantly increase the probability that discrepancies between exchange activity and tax returns are identified.The 90% figure therefore should not be interpreted as France's measured crypto tax gap. But the combination of evidence of severe underreporting elsewhere, billions of dollars in potentially taxable French activity and automatic transaction reporting beginning next year explains why crypto tax enforcement is entering a very different phase.