Take advantage of the priority mechanism
The utility certificate, a lightweight patent

The priority mechanism makes it possible to file a second application for the same invention, and to backdate the conditions of patentability to the day of filing of the first patent application for which priority is claimed.

The priority mechanism is governed by the Paris Convention (UPC), to which France is a signatory. The UPC states that the application serving as the basis for a priority claim may be a patent application or a utility certificate application (A4.E.2 UPC). As a result, a French utility certificate can serve as an earlier application for a priority claim by a subsequent foreign patent application. Conversely, a foreign patent application can serve as an earlier application for a priority claim by a subsequent French utility certificate application. It is also possible to claim priority between two utility certificates.