An undeclared bank account abroad exposes its holder to heavy penalties, separate from any tax that may be due. The law requires you to declare, every year, the accounts opened outside France, in addition to the income they produce. Many taxpayers discover this obligation late: after a period abroad, an inheritance or the opening of an online account. Our tax team, led by Maître Harry Allouche, helps you measure your exposure and return to compliance.
This page sets out the reporting obligation, the consequences of an omission and the voluntary regularisation process. It is intended for French tax residents, returning expatriates and families holding assets outside France. Every situation is different: the rules described here provide a general framework, not personalised legal advice. For an overview of our work, see the page of our tax law firm.
Declaring a foreign bank account in France: who must do it?
Article 1649 A of the French Tax Code (CGI) applies to individuals, associations and non-commercial companies domiciled or established in France. They must declare the details of accounts opened, held, used or closed abroad. This declaration accompanies the income or profits tax return every year. An account closed during the year must therefore still be declared for that same year. For individuals, it is made on form no. 3916 (in French), filed with the income tax return.
Its implementing rules are set by decree, and must be checked account by account. The text also covers accounts that are merely “used”, not only those you hold. Expatriates returning to France often keep accounts in their former country of residence. These accounts become reportable as soon as the tax domicile is again located in France. Our page on tax support for expatriates details the other points to check when leaving or returning.
Undeclared foreign bank account: what are the penalties?
Failure to declare first triggers a fixed fine under Article 1736 of the CGI. It amounts to €1,500 per undeclared account. It rises to €10,000 if the State concerned has not concluded with France an administrative assistance agreement giving access to banking information. The calculation is made account by account, which quickly adds up when there are several accounts.
The 80% surcharge on reassessed tax
Where the tax authorities reassess tax on the basis of the sums held in these accounts, Article 1729-0 A of the CGI applies. It provides for an 80% surcharge on the tax due. This surcharge cannot be lower than the corresponding fine. For the same tax, it excludes the surcharges under Articles 1728, 1729 and 1758 of the CGI.
The same regime covers capitalisation contracts taken out abroad, assets placed in a trust and crypto-assets. The logic remains the same: an undeclared asset outside France costs more than a simple tax adjustment. The combination of the fine and the surcharge justifies a prompt analysis of your situation.
The presumption of taxable income
Article 1649 A also lays down a demanding rule of evidence. Sums, securities or assets transferred to or from abroad through an undeclared account constitute taxable income, unless proven otherwise. It is therefore up to the holder to prove the origin of the funds: savings already taxed, a gift, an inheritance or sale proceeds. Without supporting documents, these flows may be treated as income.
A reassessment period extended to ten years
In principle, the tax authorities can reassess income tax until the end of the third year following the year for which the tax is due. Article L. 169 of the French Tax Procedure Code (Livre des procédures fiscales, LPF) extends this period to the tenth year in the event of a breach of Article 1649 A. A forgotten account can therefore open an audit covering an entire decade. Back taxes, surcharges and late-payment interest then accumulate over several years.
The text provides for an important exception. The ten-year extension does not apply if the taxpayer provides specific proof. The total credit balances of their foreign accounts must not have exceeded €50,000 at any time during the year. The burden of proof lies with the taxpayer, which means keeping the statements for each year concerned. This exception affects the reassessment period, not the obligation to declare.
Unexplained assets: the risk of 60% gift and inheritance duties
Article 755 of the CGI covers assets held in an account abroad, in a capitalisation contract abroad or in crypto-assets. Their origin and the way they were acquired must be justified in the procedure under Article L. 23 C of the LPF. Failing that, these assets are deemed to be wealth acquired free of charge. This presumption falls away if you provide proof to the contrary.
The financial consequence is heavy. The assets are then subject to gift and inheritance duties at the highest rate in Table III of Article 777 of the CGI. That rate is 60%. The tax base is the highest value known to the tax authorities. A documented answer on the origin of the funds therefore becomes decisive from the very first exchanges.
Request for explanations: how should you respond to the tax authorities?
Article L. 16 of the LPF allows the tax authorities to request clarifications and justifications, in particular on assets held abroad or income from them. This letter deserves particular attention, because your answers steer the rest of the procedure. An incomplete or approximate answer can weaken your position. Our method for responding to a tax information request sets out the right approach.
Before responding, it helps to know what banking information the tax authorities can already consult. Our article on FICOBA, the French national register of bank accounts (in French) presents this register and how it is used. Your answers must remain consistent with this data and with your past returns. We review each answer before it is sent to avoid any contradiction.
Regularising a foreign account: a voluntary step
Regularisation means declaring forgotten accounts and correcting omitted income on your own initiative. Article 1727 of the CGI sets late-payment interest at 0.20% per month. Its paragraph V reduces this interest by 50% in the case of a voluntary amended return. The process covers the years still open to audit, according to the applicable reassessment periods.
A serious regularisation is not just a box to tick. It requires reconstructing the history of the accounts, classifying each flow and documenting the origin of the funds. This preparation serves two purposes: declaring accurately, then being able to justify every amount if the tax authorities ask. Our page on tax regularisation with a lawyer describes the whole process.
How we assist you
Our work follows a method in several stages, adapted to the number of accounts and how long they have existed. We work from verifiable documents, never from rough estimates. Our role is to bring you back into compliance, never to conceal an asset.
- Inventory of accounts opened, held, used or closed outside France, including in a former country of residence.
- Collection of statements and reconstruction of flows, year by year, over the period still open to audit.
- Analysis of the origin of the funds and of the documents available to rebut the statutory presumptions.
- Quantifying the exposure: fines, surcharge, late-payment interest and any duties.
- Preparing the amended returns, then following up the exchanges with the tax authorities.
If the tax authorities have already written to you, we assist you with your answers and the rest of the procedure. Our fees are set out in a written agreement, as required by law. To discuss your situation in complete confidence, contact our team through the firm’s contact form.
Frequently asked questions
Do you have to declare a foreign account you rarely use?
In principle, yes. Article 1649 A of the CGI covers accounts opened, held, used or closed abroad, and refers to a decree for its implementing rules. The declaration accompanies the income or profits tax return every year: have each account checked before concluding that it falls outside the obligation.
What is the fine for an undeclared foreign bank account?
Article 1736 of the CGI provides for a fine of €1,500 per undeclared account. It rises to €10,000 per account where the State concerned has not concluded with France an administrative assistance agreement giving access to banking information.
How many years back can the tax authorities go?
In the event of a breach of Article 1649 A, the reassessment period for income tax runs until the end of the tenth year (Article L. 169 of the LPF). This extension does not apply if you prove that the total credit balances of your foreign accounts did not exceed €50,000 at any time during the year.
Does voluntary regularisation reduce the cost?
Article 1727 V of the CGI reduces late-payment interest by 50% in the case of a voluntary amended return. The final cost depends on the number of accounts, the years concerned and the sums at stake. Each file therefore calls for a case-by-case analysis.
What happens if the origin of the funds is not justified?
Article 755 of the CGI deems these assets to have been acquired free of charge, unless proven otherwise. They are then subject to gift and inheritance duties at the 60% rate in Table III of Article 777, on the highest value known to the tax authorities.
Official sources
- Article 1649 A of the French Tax Code (reporting of foreign accounts): Légifrance (in French)
- Article 1736 of the French Tax Code (fine for an undeclared account): Légifrance (in French)
- Article 1729-0 A of the French Tax Code (80% surcharge): Légifrance (in French)
- Article L. 169 of the French Tax Procedure Code (reassessment period): Légifrance (in French)
- Article 755 of the French Tax Code (unexplained assets abroad): Légifrance (in French)
- Article 1727 of the French Tax Code (late-payment interest): Légifrance (in French)
Law as in force on 1 October 2026. Content written under the responsibility of Maître Harry Allouche. This content provides general information and does not constitute legal advice. Every situation is different: the firm commits to the means it deploys, without any promise of outcome.
