To audit and calculate the real property tax, in order to detect unfair situations and cases of surcharge, the normal way is to ask the French tax administration a copy of the file of  the building.

This will give you the information about the reference premises chosen by the tax administration to tax your own building, and will allow you to see if this selection is appropriate.

Sometimes the answer of the French tax administration ("Centre des impôts foncier", or CDIF) is delayed, so a better choice can be to go directly to the source and try to find the reference premises directly, to be able to discuss its land registry rental value. This approach won’t always bring a positive result if several reference premises have close rates, but it is often saving time.

To use this approach, it is necessary to gather :

- The last tax demand of the real property tax,

- The Report gathering all the reference premises of the “Commune” (Form n° 6670) : a document that you have to pay (expensive for big cities), which can be obtained from the CDIF (see model under the heading "Forms")

- The table of county coefficients from 1970 to 1980,

- The table of national cumulative coefficients from 1981 to 2007,

- The number of square meters of your building.

The possibility to ask the only page of the Form n° 6670 where is the reference premises chosen by the tax administration, is not a good solution, because, if you have not all the pages of the Form n° 6670 you won’t be able to realise a comparative analysis between the reference premises used by the tax administration and all the reference buildings of the “Commune” (see "The 10 Steps" of the process).

From the tax demand, you can go back to the assessment basis of the building.

  1 - Start from the tax demand

On the tax demand of the real property tax on developed land appears the assessment basis of that tax, which, after multiplication by the annual rate, is giving the amount of the annual real property tax.

For example, take an assessment basis of 10.000 Euros for a business building located in Toulouse.

The assessment basis for the developed land, is 50% of the registry rental value of the building. So, in our example, the registry rental value of the building in 2007 is 20.000 Euros.

  2 - Determine the registry rental value of the building in 1970

For this point, two operations are necessary :

Remove the impact of the cumulative national coefficient used for the years 1981 to 2007.

You’ll find the coefficient table and cumulative coefficient table for buildings other than industrial buildings (under the accounting method) in the "Diagnosis" chapter of the site.

The national coefficient in 2007 is 1,018. The cumulative national coefficient from 1981 to 2007 is 2,688.

Result = 20.000 : 2,688 = 7.440.

Remove the impact of the county (“département” of Haute-Garonne, code n° 31) coefficient from 1970 to 1980.

You’ll find the table of county coefficients from 1970 to 1980, concerning the buildings other than industrial buildings (under the accounting method) in the "Diagnosis" chapter of the site.

The county coefficient for Haute-Garonne (in this example) is 1,88 (for commercial premises).

Result = 7.440 : 1.88 = 3.958.

The registry rental value of the building in 1970 was to 3.958.

  3 – Evaluate the surface of the building

For commercial premises, the surface of the building is weighted.

From the real surface, the calculation of the weighted surface will use the surface weighting Table for commercial premises located in the "Diagnosis” Chapter of the site.

To simplify, the approximate result is :

- the surface of the first 5 meters deep is weighted to 1 and beyond, to 0,5.

- the rear shops, reservations, etc. are weighted to 0,33,

- the basement is weighted to 0,20 and the cellar and attic to 0,10.

Suppose premises with a 350 m2 real surface (50m facade x 7m) : the weighted surface will be (front 50m x 5m x 1 = 250 m2 weighted) + (2m x 50m x 0.5 = 50 m2 weighted) = 300 m2 weighted.

Concerning premises for residential use or professional premises (different from commercial premises), a weighting of the surface needs also to be realised. You will find, to help you, a file for this sort of premises in the "Diagnosis” Chapter of the present site.

  4 - Reduce the registry rental value from 1970 in weighted m2, and compare the result with the tariff of the reference premises chosen by the tax administration

The registry rental value from 1970 (3.958) divided by the number of weighted m2 (300) sets the tariff by weighted m2 (13,19 Euros).

This tariff (13,19 Euros) must match the reference premises tariff (see Form n° 6670 : Report gathering all the reference premises of the “Commune”) chosen by the tax administration to tax your building.

Then, you will have to determine whether the choice of the reference premises was appropriate or not.

Although the weight of regions and departments (counties) in local taxation is currently much lower than the one of the “Communes”, a risk exist that this weight would increase in the years to come.