Crypto-assets have long been perceived as a grey area that slips under the tax authorities’ radar. Bitcoin, anonymous wallets, foreign platforms… all these tools seemed to offer a loophole to taxpayers tempted by a lack of transparency. But those days are over. By 2025, the French tax authorities had developed specific audit methods to detect and penalise omissions or fraud relating to crypto-assets.
Behind what is still a technical façade, a simple principle prevails: every crypto-asset must now be traceable, declared and accounted for.

Strict reporting requirements

The first area to be checked is the declaration.

• All taxpayers must declare any accounts they hold with foreign platforms (Form 3916-bis).

• Accounts held with foreign digital asset service providers (DASPs) must also be declared.

• Failure to declare will result in a fine of €750 per account, increased to €1,500 if the account is held in a non-cooperative country.

Furthermore, any disposals must be included in the annual tax return, with a separate annex covering capital gains from the disposal of crypto-assets. Failure to do so, even if unintentional, may result in a tax reassessment.

The administration’s extensive powers

The DGFiP has powerful tools at its disposal for detecting irregularities:

• Requests for supporting documentation (Article L16 of the Financial Proceeds Act) enable authorities to demand statements, transaction histories and explanations regarding crypto transactions.

• In the event of an inadequate response, an ex officio assessment (Article L73 of the LPF) may be applied, with an 80 % surcharge in the event of fraudulent conduct.

• As part of a personal tax review (ESFP) or an accounts audit, the tax authorities may cross-check declared income against expenditure and require evidence of the source of funds.

Taxpayers need to understand that, when it comes to a crypto portfolio, the tax authorities treat it in the same way as any other asset: if a lifestyle is inconsistent with declared income, taxation may be imposed.

Closer cooperation with TRACFIN and at international level

The DGFiP does not work alone. Crypto transactions are now on the radar of TRACFIN, which is responsible for combating money laundering, and specialist agencies (BVCI, the police, the gendarmerie).
Above all, the automatic exchange of information is being extended to platforms:

• At European level, the DAC8 Directive requires PSANs to pass on client data to tax authorities.

• At international level, the OECD’s CARF (Crypto-Asset Reporting Framework) aims to establish the same level of transparency as for bank accounts.

The idea is simple: it is becoming virtually impossible to hide one’s crypto assets abroad.

Seizures and recovery: crypto in the spotlight

The authorities are also making progress in the area of debt recovery:

• Administrative attachments against third-party holders (SATD) may relate to assets held with PSANs domiciled in France.

• Judicial cooperation makes it possible to freeze assets held abroad.

• Several recent cases have shown that crypto-assets are not immune to seizure by criminal and tax authorities.

Here again, the logic is clear: cryptocurrency is not an exception, but an asset like any other, subject to the same recovery procedures.

Professionals and active investors who are particularly exposed

As well as private individuals, industry professionals and high-volume investors are under increased scrutiny.

• Activities such as mining or regular trading may be reclassified as undeclared business activities, with serious consequences: corporation tax, VAT and social security contributions.

• Repeated breaches may result in the case being automatically referred to the public prosecutor’s office on grounds of tax fraud, particularly if the thresholds of €100,000 or €50,000 are exceeded.

Conclusion

Tax audits of crypto-assets are no longer a figment of the imagination: they are an everyday reality for the DGFiP. Tax returns, supporting documentation, international cross-checks, seizures… all the tools are now in place.
Taxpayers must realise that crypto is no longer a blind spot in the French tax system. The opacity of the past has been replaced by organised transparency, underpinned by unprecedented international cooperation.

At Qualifisc, we support individuals and businesses in bringing their crypto-asset transactions into compliance, ensuring their security and safeguarding their interests.