Forgot to Declare Foreign Income or an Account in France? How to Fix It

Leaving something off your tax return is easy to do, foreign dividends, interest, rental income, a bank account held abroad, a Luxembourg life insurance policy, or a tax reduction filled in wrong. The good news is that a genuine, good-faith mistake can usually be put right. The one thing you shouldn't do is leave it unaddressed.

What happens if you forget something?

It depends on the nature of the omission.

A taxable income wasn't declared. The tax authorities can recalculate the tax due and ask for the extra tax, late-payment interest (generally 0.20% a month, or 2.4% a year), and possibly a 10% surcharge. That said, the "right to make a mistake" (droit à l'erreur) usually lets you avoid the surcharge when you correct a good-faith omission of your own accord. A voluntary amended return can also halve the late-payment interest, under certain conditions set out in Article 1727 of the French General Tax Code.

A foreign bank account wasn't declared. A bank or securities account opened, held, used or closed abroad generally has to be declared each year with form 3916-3916 bis, under Article 1649 A. Forgetting can cost €1,500 per undeclared account, rising to as much as €10,000 per account in certain countries or territories.

A foreign life insurance policy wasn't declared. Policies taken out with an insurer based outside France generally have to be declared with form 3916-3916 bis, via box 8TT, under Article 1649 AA. The fine can reach €1,500 per policy per non-time-barred year, or €10,000 in some situations.

What to do, step by step

Step 1: Pin down exactly what was missed. Before doing anything, gather the details: the year concerned, the nature of the income or account, the gross amount of the income, any tax already paid abroad, the documents from your bank, broker or insurer, the account or policy number, and the periods during which it was held.

Step 2: Check whether the omission changes your tax. Some omissions don't necessarily create extra tax, a foreign account that generated no taxable income, for instance, still had to be declared even though nothing is owed. So you may need to correct two separate things: the missing income, if there is any, and the account, policy or investment that wasn't reported.

Step 3: File an amended return. For missing income, you correct the return for the year concerned, either online while the correction service is open, or through the secure messaging in your personal tax space, explaining the error and attaching the necessary documents. For a foreign account or policy, complete form 3916-3916 bis for each one concerned.

Step 4: Explain the situation clearly. In your message to the tax office, simply set out what was missed, the year or years involved, the reason for the oversight, the corrections made, and the documents attached. Being precise and transparent helps, a voluntary correction is generally received better than an omission uncovered during an audit.

Step 5: Pay any top-up quickly. If the correction produces extra tax, pay it as instructed. Paying promptly limits the interest and shows the step was voluntary.

What if the tax office has already written to you?

Reply within the deadline given in the letter. A correction made of your own accord, before any binding procedure begins, is generally treated more favourably. Once you've received a formal notice, a proposed adjustment or certain audit steps, an amended return is no longer considered fully voluntary. Even so, once an audit has started it's still better to regularise and answer honestly, in some cases a formal regularisation procedure can reduce the late-payment interest.

A word on foreign omissions

Foreign accounts and policies are subject to automatic exchange of information between tax authorities. Financial institutions can pass on the holder's identity, tax residence, account balance, financial income, and the surrender value of a life insurance policy, a process framed by Article 1649 AC. In other words, it's unwise to wait and hope the authorities never notice, they increasingly do.

The takeaway

A good-faith error isn't automatically treated as fraud. The right move is to regularise as soon as you spot the omission: an amended return usually limits the surcharges, and while late-payment interest may still apply, it can be reduced when you come forward voluntarily. Bear in mind that foreign accounts and life insurance policies can trigger specific fines even when no tax is due, and keep a copy of your correction and of everything you exchange with the authorities.

Living in France and unsure about your tax obligations?

If you are an expatriate living in France and have questions about your French tax return, foreign income or the interaction between French taxation and your home country's tax system, you can book a free introductory call to discuss your situation and identify the key points that should be checked.

Disclaimer: This article is for general information and educational purposes only. It is based primarily on official French government sources and other trusted references. It does not constitute personalised tax, legal or financial advice. Tax filing obligations depend on individual circumstances, the country concerned and the applicable tax treaty.