A large share of cryptocurrency-related profits generated in France appears to have gone undeclared, according to new on-chain analysis from blockchain intelligence firm Chainalysis. The company’s Crypto Tax Report estimates that French residents generated about $9.4 billion in potentially taxable crypto activity during 2025.
That figure placed France 13th among the markets Chainalysis examined and formed part of a global total of more than $457 billion in on-chain activity that could, depending on local rules, give rise to tax obligations.
The French total was broken into three categories: roughly $2.5 billion in realized capital gains tied to trading on centralized and decentralized platforms, $1.7 billion in income from sources such as mining, staking, lending and related activities, and $5.2 billion in crypto payments.
Chainalysis stresses that these are estimates of activity that could be taxable, not a precise calculation of unpaid tax.
Payments, for example, are not the same as taxable profit, and different income streams can fall under different regimes. Still, the gap with official filings is striking.
French tax data show that about 24,000 taxpayers reported a combined €368 million in net crypto capital gains for the 2024 income year.
That was a sharp rise from the previous campaign, when roughly 7,700 people declared about €150.8 million.
Even so, declared net gains remain a small fraction of the on-chain volumes researchers attribute to France.
Chainalysis has noted that non-compliance rates in some countries can exceed 90 percent, citing patterns seen elsewhere, including Sweden.
François Volpoet, who leads the firm’s work in France, has linked that estimate to the same mismatch between blockchain activity and tax returns.
France taxes net crypto capital gains at a flat 31.4 percent, with only a modest annual exemption of €305.
In practice, most realized profits above that threshold are reportable. Using crypto to buy goods or services is generally treated as a taxable disposal.
The reporting increase between the two most recent campaigns suggests growing awareness, but the scale of on-chain activity still far outstrips what has been declared.
Chainalysis also cautions that its numbers may understate the true picture because many trades that stay inside a single exchange never appear clearly on public blockchains.
The timing matters.
The European Union’s DAC8 rules took effect on 1 January 2026. Crypto-asset service providers must now collect identifying information and transaction data on EU-resident customers.
Cross-border exchange of those records among tax authorities is scheduled to begin on 30 September 2027.
The OECD’s Crypto-Asset Reporting Framework is moving in the same direction.
Chainalysis estimates, however, that only about 14 percent of potentially taxable on-chain activity currently falls within the practical reach of CARF-style reporting.
The rest involves decentralized exchanges, peer-to-peer transfers, private wallets and certain forms of on-chain income that are harder to attribute automatically.
Activity is also highly concentrated.
In France, 37 percent of relevant addresses accounted for 93 percent of taxable volume, a pattern that could help authorities focus limited enforcement resources.
Global context underlines the same point: the United States led with an estimated $112.6 billion in potentially taxable activity, followed by Germany and China.
Across countries, on-chain crypto income typically represented 1 percent or less of GDP under the firm’s conservative method.
The coming reporting regime will not capture every transaction. Decentralized and peer-to-peer activity will remain harder to police.
Even so, the combination of mandatory data collection by regulated platforms and better on-chain analytics is likely to shrink the space in which unreported gains can sit unnoticed. For French taxpayers who have treated crypto as largely invisible to the tax authority, that window is closing.