The prosecution of a French patent application

Immediately after filing

An examination as to the form is carried out. In case of irregularities, a period (generally one month) is given to the applicant for regularizing the application.

In case of non-unity of the invention, the applicant is asked to file a divisional application within 2 months from the notification. This objection can be contested.

In case of priority claiming, the priority document must be filed within a 16-month period from the priority date.

Preliminary Search Report

The Examination of the patent application must be requested at the filing.

In the absence of priority claimed, the French Office of Industrial Property (INPI) sends a preliminary search report about 9-10 months after filing. It contains references which may be taken into consideration as to novelty and inventive step, as well as a Written Opinion of the Examiner regarding the patentabilty.

If particularly relevant references are cited, the applicant must answer within a 3-month period once renewable. The response consists either in observations or in amendments to the claims.


18 months after the filing or priority date, the patent application is published in the Official Bulletin of Industrial Property (BOPI), as well as the preliminary search report (citing the cited references) if available (if not, it will be published at a later date).

From the publication, third persons have a 3-month period to file observations and to cite references. The applicant then has to respond within a 3-month period once renewable from the notification of the observations. This procedure is in fact rarely used.

Grant of the patent

After the examination procedure, which can take 2-4 years, the INPI indicates that the patent is about to be granted. The granting and printing fee has to be paid. The certificate is then delivered about 4 to 8 months later.

Without any further requirements, protection of a patent in France gives also rights in the "Overseas Departments" (Guadeloupe, Martinique, Reunion and French Guyana), in the "Overseas Territories" (Wallis and Futuna, the French Austral Islands and the French Antartic territories), in the "Territorial Collectivities" (St Pierre and Miquelon, Mayotte) and in New Caledonia and dependencies.


An opposition period of nine-months starting as from the date of grant of the French patent is available to third parties, without having to prove standing, to file an opposition on the grounds of lack of patentability, insufficiency of disclosure and extension of subject-matter of the granted patent with respect to the application as filed.


Any transfer or modification of the rights (assignments...) or any modification regarding the owner (name, address...) shall be recorded as soon as possible in the National Register of Patents in order to always be opposable to third ones.

Renewal fee

Patent is a title delivered for a term of 20 years from the filing date. However, renewal fees have to be paid each year, from the filing, in order to maintain this title in force, at the end of the anniversary month of the filing.

Working out

A patent owner has the obligation of working out the patent. The lack of working out in a state member of the EEC for a 3-year period from the grant of the patent or 4-year period from the filing date (the longer one) or an insufficient exploitation allow a third person to ask for a compulsory licence.