TLDR: In the event of a change in the use of business premises, the owner must declare it to the tax office where the property is located within 90 days of its final completion. The declaration is made using a form similar to that for new construction, with supporting documents such as the declaration of change of use or a copy if the change occurred earlier. Changes in use made after January 1st of a given year are only taken into account from the following year.
Declaration obligation
The owner is required to declare the change in the use of business premises to the competent tax office. This obligation applies regardless of the owner's status (individual, company, micro-entrepreneur).
Declaration deadline
The change must be declared within 90 days of its final completion. This period starts from the date on which the state of the work allows the premises to be used in accordance with the new intended use.
Declaration procedures
The declaration is made by submitting a form identical to the one used for new construction. The owner must provide supporting documents, such as the declaration of change of use or a copy if the change occurred earlier.
Consideration of changes
Changes in use or in the method of determining the rental value made after January 1st of a year are only taken into account from the following year's tax assessments. This means that a change made in January of year N will be applied from year N+1.
Special cases and supporting documents
To justify the change in use, the declaration of change of use or a copy of it is sufficient. No additional documents are required unless specifically requested by the tax authorities.
Impact on rental value
The change in use may result in a modification of the cadastral rental value of the premises, with consequences for local taxes (property tax, CFE). This update follows the general rules for revising rental values.