Filing a French patent or a French certificate of utility?

The main differences between a French Patent and a French Certificate of Utility are :


Patent : 20 years from the filing date.

Certificate of utility : 10 years from the filing date.


Patent : A preliminary search report is done by the European Patent Office for the French Office (usually 9 months after the filing when no priority is claimed). The applicant may or has to (in case of documents cited in category X or Y) amend the claims as filed or file observations in response to the search report.

The official fee for requesting the preliminary search report is of 520 EUR (260 EUR for a small entity).

Certificate of utility : No search report is done

The patentability conditions are the same : novelty; inventive step; industrial applicability.

Duration of the prosecution till grant

A Patent application (like a Certificate of Utility) is published 18 months after the filing date or the priority date, if any. Generally the grant of patent takes place 2 to 3 years after the filing and the grant of a certificate of utility takes place 2 years after the filing.

It is possible to accelerate the granting of a certificate of utility by requesting earlier publication.


The conversion of a certificate of utility application into a patent application is possible within 18 months from the earliest filing date of the certificate of utility application.

What happens in case of an action for infringement ?

Certificate of utility : The plaintiff shall request the establishment of the preliminary search report. However, the proceeding does not permit to amend the claims in order to take into account the prior arts.

This is an important inconvenience. This is why filing a patent application seems always a better way to obtain rights on an invention.