French authorities have put forward a proposal that would impose fines of €10,000 on individuals who fail to declare cryptocurrency wallets holding more than €100,000, according to a report by the Bitcoin Foundation. The measure targets the disclosure gap around large digital asset holdings, one of the few areas of crypto activity that still escapes routine reporting in France.

The proposal centers on a simple compliance test: if a wallet — whether self-custodied or held through a service provider — crosses the €100,000 threshold, its owner would face a reporting obligation. Non-disclosure would carry the proposed €10,000 penalty. For French holders, the effect would be to extend the logic of existing financial-account reporting rules directly onto blockchain-based assets.

What does the proposal actually require?

Under the draft measure, the obligation attaches to the wallet balance rather than to the intermediary. That distinction matters. France already requires residents to declare foreign accounts, including accounts opened with foreign crypto service providers, when annual balances exceed €15,000. The new proposal goes further by covering holdings that may sit entirely outside any regulated intermediary.

The key operational features, as reported:

• A €100,000 wallet-value threshold triggers the disclosure duty.
• Failure to disclose carries a proposed fine of €10,000.
• The obligation would reach self-custodied wallets, not only exchange accounts.

If enacted as described, the measure would place the compliance burden on individuals rather than on platforms. Exchanges and custodians already transmit data under EU frameworks; self-custodied holdings have been the blind spot. A wallet-level reporting rule closes that gap administratively, but it also creates an enforcement problem for the tax and customs authorities, who must reconcile voluntary declarations against on-chain records they cannot fully see.

How does this fit France's existing crypto tax architecture?

France taxes gains on crypto asset disposals as industrial and commercial profits for active traders and under a flat tax regime — currently 30 percent including social levies — for occasional investors. Declaration requirements already exist at the annual tax return level. The proposed €10,000 fine adds a punitive layer for non-disclosure of large balances, effectively treating wallet opacity as an offense in itself rather than merely an underreporting issue.

The €100,000 threshold signals that the proposal is aimed at substantial holdings, not retail users. It also aligns with a broader European direction of travel: since the EU's Markets in Crypto Assets regulation and the Transfer of Funds Regulation's travel rule, regulators have increasingly sought visibility into the full chain of custody, including unhosted wallets.

What are the practical consequences for holders?

For French residents with large crypto positions, the proposal would create a new annual compliance task with a five-figure downside for failure. Compliance teams at French financial institutions and crypto service providers would likely see increased demand for wallet valuation statements and balance attestations, since taxpayers will need documentary support to prove disclosure. Legal advisers can also expect disputes over valuation methodology — whether the €100,000 threshold applies at year-end, on a transaction-date basis, or at any point during the period, and how volatile assets are measured against the line.

Self-custody users face a more structural question. Unlike a bank account, an unhosted wallet generates no counterparty statement. Proving compliance — or contesting an alleged non-disclosure — would rest on the holder's own records, blockchain analytics, or both.

What happens next?

The measure remains a proposal and would need to pass through France's legislative process before the €10,000 penalty takes effect. Holders and industry groups will scrutinize the final text for definitional clarity on wallet valuation and the disclosure mechanism. If France enacts the rule, it would become one of the first major EU jurisdictions to attach an explicit administrative fine to non-disclosure of self-custodied crypto holdings above a fixed threshold — a template other European tax authorities could follow.