Chainalysis: Over 90% of France’s Crypto Gains Go Undeclared

The Two Numbers That Don’t Match

A quick look at the numbers and the problem states itself. Blockchain analytics firm Chainalysis puts potentially taxable crypto activity in France at $9.4 billion for 2025, split into $5.2 billion in payments, $2.5 billion in capital gains and $1.7 billion in income from sources such as mining and staking.

French tax filings tell the story as follows:

• For the 2024 income year, about 24,000 individuals declared a combined €368 million ($427M) in net gains.
• The figure was up from roughly 7,700 taxpayers and €150.8 million ($175M) the year before, but still a fraction of the activity the chain records.

The two figures are not strictly comparable given taxable activity is not the same as taxable profit, and only the gains component of that $9.4 billion would translate into a capital gains bill. Even after that adjustment, the distance between what the blockchain shows and what the state sees remains wide.

Chainalysis has said non-compliance may exceed 90% in some countries, an estimate François Volpoet, who directs the firm’s France operations, has tied to exactly this pattern of underreporting. The company’s own report reaches for a comparison from Sweden, where it notes more than 90% of people did not report their crypto activity.

What Chainalysis Actually Measured

The France number sits inside a global exercise as Chainalysis estimates more than $457 billion in potentially taxable onchain activity worldwide during 2025. To elaborate:

• Europe accounted for $125.1 billion of that total.
• United States accounted for $112.6 billion.
• China registered about $21 billion despite an onshore trading ban.

France’s rules make the stakes concrete since net capital gains from crypto face a flat rate of 31.4%, with an annual exemption threshold of just €305 (approx. $350), meaning the vast majority of realized profits are technically reportable. Applied to billions in activity, a 90% miss rate is not a rounding error.

The 2027 Deadline

The European Union’s eighth Directive on Administrative Cooperation, known as DAC8, took effect on Jan. 1, 2026. It requires crypto service providers operating in member states to collect detailed identity and transaction data on their users and hand it to national tax authorities. Those authorities then begin exchanging records across borders from Sept. 30, 2027.

DAC8 is the EU’s implementation of the Crypto-Asset Reporting Framework, or CARF, an Organization for Economic Cooperation and Development standard that dozens of countries have committed to adopting. The effect is to move crypto onto the same automatic information-sharing footing that banking has operated under for years.

However, as expected, not everyone seems to be cool with the directive. For instance, crypto exchange Bull Bitcoin has mounted a legal challenge in France seeking to strike down the decree implementing DAC8 in national law.

The 86% That Still Escapes

Chainalysis calculates that CARF captures only about 14% of global taxable activity, leaving roughly 86% outside its practical scope. The gap, however, is structural given CARF is built around centralized intermediaries that already identify their customers. Self-custody wallets, decentralized exchanges, peer-to-peer transfers and onchain income streams have no intermediary to compel, so they generate taxable events that no reporting regime currently sees.

There is a second problem specific to France. The country has recorded 36 physical attacks on crypto holders in the first eight months of 2026, 64% more than in all of 2025, with leaked tax authority data among the factors blamed. Collecting more identity data solves one problem while sharpening another.