Written opinion

The written opinion is the reasoned view in which the examiner, at the time of the prior art search, gives a provisional assessment of whether the patent application meets the conditions of patentability. It accompanies the preliminary search report drawn up by INPI, the extended European search report of the European Patent Office and the international search report drawn up by the International Searching Authority under the Patent Cooperation Treaty. It is not a decision and has no legal effect of its own, but it decisively shapes the rest of the procedure.

Content of the opinion

The written opinion states, claim by claim, whether the invention appears to be new, to involve an inventive step and to be susceptible of industrial application in the light of the documents cited in the search report. It also raises objections relating to the clarity of the claims, unity of invention, support for the claims in the description and the exclusions from patentability. The opinion thus foreshadows the objections that the Examining Division will maintain if the applicant does not overcome them.

The applicant’s response

Before INPI, the applicant may file observations and new claims in response to the opinion, within the period set in the notification of the preliminary search report, which leads to the final report being drawn up. Before the European Patent Office, where the opinion is negative, the applicant must respond to the objections for examination to proceed, failing which the application is deemed withdrawn. In the international procedure, the written opinion of the International Searching Authority is sent to the applicant, who may respond with informal comments or request international preliminary examination in order to obtain a revised report. The international opinion is then communicated to the designated offices in the form of an international preliminary report on patentability, which each office assesses freely during the national phase.

Weight and use of the opinion

The written opinion binds neither the office, which may raise new objections during examination, nor the court, which assesses the validity of the granted patent without reference to it. It is nonetheless a decision-making tool for the applicant, who can read in it the chances of grant and the likely scope of protection before incurring the costs of extension abroad. Concessions made in response to the opinion are on the file and may be raised against the patentee in later patent infringement proceedings, so that the response must be drafted with care not to narrow the interpretation of the claims unnecessarily.

Key points

The written opinion is the examiner’s provisional view on patentability, attached to the French, European or international search report. It binds no one but foreshadows the objections in examination and indicates the chances of grant. It should be answered within the time limits, with reasoned argument and amended claims where necessary, and each concession should be weighed against its effect on the scope of the patent in future litigation.

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This glossary entry is general in scope and does not constitute legal advice.

Dhenne Avocats litigates patent disputes before the Paris Judicial Court, the Paris Court of Appeal and the Unified Patent Court. When the question arises in a real case, the right moment is almost always before proceedings are issued.

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