Each year, there are around 650,000 to 900,000 tax audits per year on individuals in France. A drop in the ocean compared to the 40 million tax households, but you should know that the tax administration does not choose them at random. There are signs that attract tax inspectors to certain profiles, which is why you must be particularly vigilant when completing your tax return.
In addition, since 2024, the administration has had automated detection tools that cross-reference your declaration with your bank statements, your real estate transactions, your classified ads and even your social networks. Nearly one in two tax audits is now motivated by AI. So what can attract the beam to you and trigger a tax audit?
A brutal variation in income from one year to the next
This is the most common signal. When your declared income decreases or increases sharply from one year to the next without any apparent explanation, the system detects it. A 40% drop in declared income will immediately raise questions about an omission, an undeclared activity, or a poorly reported change in situation. Conversely, a sharp increase may signal an undeclared capital gain or forgotten incidental income.
But if your situation has really changed, a line of explanation in the observations section of your declaration may be enough to avoid a request for justification.
A lifestyle incompatible with your declared income
A taxpayer who declares 35,000 euros per year but buys several real estate properties in a few years, or even a luxury car, automatically finds himself on the radar. This signal can trigger what the tax authorities call a contradictory examination of the personal tax situationor ESFP: an exceptional procedure during which the administration will reconstitute your budget over several years, by comparing your declared income with your assets, your acquisitions, your expenses and your real standard of living.
The administration is able to conduct online investigations, including under pseudonyms on advertising sites or social networks (Facebook, Instagram or TikTok), to search for evidence of undeclared activities.
Income from investments and foreign accounts often forgotten
Dividends, interest, rent, capital gains on the sale of cryptocurrencies: this income must be declared even when they are modest. The tax authorities, for their part, receive the IFU (Unique Tax Forms) from your banks and insurers, and can therefore compare what was sent to them with what you declared. A deviation, even unintentional, automatically generates a request for justification. Cryptocurrency platforms are also required to transmit to the administration the data of their French tax resident customers. This sector has been the subject of particularly active surveillance since 2024.
Likewise, any bank account, life insurance contract, account on a crypto platform or any other investment held outside France must be declared each year via form 3916-bis, even in the absence of income. The fine for forgetting is 1,500 euros per account, and 10,000 euros if the account is domiciled in a country that has not signed an administrative assistance agreement with France.
