Responding to Written Opinions at the European Patent Office


Search reports prepared on European patent applications include an accompanying written opinion, to which a response is required. Different deadlines apply to different types of European patent application.

A summary of what is required is set out below

  1. For direct European applications, a response is required by the deadline for requesting examination. This deadline is six months from the publication of the search report.
  2. For the European Regional Phase of PCT applications for which the EPO was not the International Searching Authority, a response is required within a deadline set after the supplementary search report and written opinion are issued. In general, the EPO sets a six-month period for this. For such applications, a separate, earlier, six-month period is set for filing voluntary amendments before the supplementary search report is prepared. It is possible to file comments in response to the International Preliminary Report on Patentability (that is, the written opinion accompanying the international search report) at that stage, but it is not essential to do so.
  3. For European regional phase applications for which the EPO was the ISA or IPEA, a response is required within a six-month period set shortly after entry into the European regional phase.

Any voluntary amendments must also be filed by these deadlines. Later voluntary amendments can only be made with the Examiner’s consent.

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