How to determine if your French property tax bill is correctly calculated

Many French homeowners could be overpaying on property tax because the necessary information used to calculate their bills is out of date or incorrect. 

With France’s 2026 taxe foncière avis de paiement having already been sent to many people, recipients can check the information used to calculate it. 

Lawyers Manon Bellin and Gary Cahn, founders of Orka.tax, an online property-tax checking service, said they have identified overpayments in a large proportion of the cases they examined. 

Around 87% of 1,351 cases they received up until now were overvalued, with an average difference of €260 per property per year.

Why can a property be incorrectly assessed? 

French taxe foncière is based on the property's valeur locative cadastrale, an estimated rental value based on the property’s characteristics recorded by the tax authorities. However, exemptions exist for some property owners dependent on age and income.

The problem, according to Ms Bellin, is that much of the information dates back decades. 

“There is an obligation to make a declaration when the property is built,” she told The Connexion. “But afterwards there is no obligation to make an annual declaration of all the elements mentioned.

“If the person doesn't update it, the information used for the calculation is still the information from when the property was built.”

This can become an issue because while property becomes older, the coefficient d'entretien used to reflect its condition can remain unchanged.

A new property can, according to Ms Bellin, receive a coefficient that adds around 20% to its weighted surface for tax purposes, but this figure may not reflect the condition of the property as it ages.

“If we correct the tax base for taxe foncière, this can also reduce the taxe d’habitation payable on second homes, because the same rental value is used as the basis for both taxes,” Ms Bellin said.

The most common errors

Another source of confusion is the way certain facilities are incorporated into the calculation.

The tax calculation can add so-called fictitious square metres for facilities such as bathrooms and heating.

“A bath adds five square metres to the weighted surface, a shower adds four square metres, and the number of heated rooms adds two square metres per heated room,” Ms Bellin said.

These figures are not physical floor space. They are part of the system used to calculate the property's taxable rental value.

These details also can remain unchanged even if the property has been changed.

Ms Bellin said they also often encounter duplicated information, incorrect updates, outdated property categories and errors involving garages, gardens and other outbuildings.

One example involved a property where a garden had been treated as built space. Built spaces are taxed higher as living areas increase the property’s value.

Ms Bellin said the company recently arranged a reimbursement of €1,600 for one homeowner after the garden attached to an apartment had been incorrectly included as built property. The reimbursement covered six years. 

How can homeowners check?

The first step is to obtain the property’s fiche d'évaluation cadastrale, which contains the detailed information behind the rental value calculation.

Homeowners can request this from the impots.gouv.fr  website through their secure messaging service. “Ask for the assessment sheet,” Ms Bellin said. 

“However, understanding the calculation requires a certain number of things. It is not straightforward to calculate.”

Orka.tax offers a free simulator which asks for information such as the town, surface area, condition of the property and number of bathrooms and washbasins.

“It takes 60 seconds and it's free,” she said.

The simulator does not tell you if a tax bill is wrong but rather gives you an initial estimate of how much you should be paying, which can help you decide whether it is worth investigating the assessment in more detail.

What if you find an error?

A homeowner who believes the information held on their property is wrong can make a claim to the tax administration, however you will need to prove the error. 

“If you want to say that the apartment is 60 square metres and not 90, you need to have a plan that is properly established,” Ms Bellin said.

Other errors may be easier to demonstrate. For example, photographs can potentially help establish the presence or absence of particular fixtures.

“If we want to say that there is a shower rather than a bathtub, for example, a photograph is acceptable,” she said.

Can you get previous years' tax back?

Ms Bellin said the standard legal rule allows a taxpayer to receive a refund for the current and the previous year. 

For example, a claim made before the end of 2026 could cover 2026 and 2025. Additionally, homeowners who have already paid can still make a claim.

“Payment does not prevent a subsequent refund,” Ms Bellin said.

According to Ms Bellin, taxpayers can ask for an additional four years through what is known as a délai gracieux, where the tax administration is considered responsible for the error.

This can potentially bring the period covered to six years.

“We always ask for it,” Ms Bellin said, adding that the tax office does not necessarily grant the additional period in every case.

What happens if the tax office says no?

A refusal is not necessarily the end of the process either. Ms Bellin said taxpayers can first approach the tax conciliator, with one available in every department.

If that does not resolve the matter, a taxpayer can also take the case to the administrative court.

“Refusal is for a failure of justification in almost all cases,” she said, showing how important it is to have the proper evidence attached.

For homeowners who want to investigate further, Orka.tax offers a paid service which obtains the official assessment sheet and compares its contents with the information supplied by the owner.

The company said this costs €78 and they also prepare the documentation for the claim and accompany the client until the dossier has been filed with the relevant authority.

Have you ever made a claim like this to the tax administration? How did it go? Let us know at feedback@connexionfrance.com