International search and written opinion (PCT)

The international search is the documentary search carried out on every application filed under the Patent Cooperation Treaty in order to discover the relevant state of the art. It is entrusted to an International Searching Authority, chosen from among the approved offices according to the receiving Office and, where applicable, the applicant’s choice. It results in an international search report, governed by Articles 15 to 18 of the Treaty, and a written opinion on the patentability of the claimed invention.

The report and the written opinion

The report lists the prior art documents, classified according to their relevance to novelty and inventive step. The written opinion, drawn up at the same time, gives a preliminary and non-binding assessment of the novelty, inventive step and industrial applicability of the claimed invention. The report is published with the international application, in principle eighteen months after the priority date. For applications filed with INPI acting as receiving Office, the competent authority is the European Patent Office (EPO).

Options open to the applicant

The applicant may amend the claims before the International Bureau under Article 19 of the Treaty, within two months of transmittal of the report or sixteen months of the priority date, whichever expires later. The applicant may also file informal comments on the written opinion, or file a demand for international preliminary examination, which opens a dialogue with the examiner and the option of amending the description and claims. Finally, a supplementary international search, carried out by another authority, may be requested in order to broaden documentary and linguistic coverage.

Weight of the report and the opinion

Neither the report nor the opinion binds the designated Offices, which retain their freedom of assessment. Their influence is nonetheless considerable, since they usually foreshadow examination in the national or regional phase. Where no preliminary examination has been demanded, the written opinion is carried over into the international preliminary report on patentability. Before the EPO, a response to the written opinion is required at the start of the European phase of the Euro-PCT application where the EPO itself drew it up.

Key points

The international search report and the written opinion provide, before any national expenditure, a first assessment of the patentability of the invention. They bind no Office but strongly shape the rest of the procedure. They should be analysed as soon as they are received, a prompt decision should be taken on whether to file Article 19 amendments or demand preliminary examination, and the consequences should be drawn for the choice of countries and the national phase budget.

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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. Where the question arises in a real case, the useful moment is almost always before proceedings are issued.

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