When is a further written opinion issued during international preliminary examination?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

A further written opinion should be issued when:

• The applicant provides a persuasive argument that the written opinion from the International Searching Authority was improper regarding novelty, inventive step, or industrial applicability.
• The examiner considers any claims to lack novelty, inventive step, or industrial applicability based on new art not necessitated by amendments.

According to the MPEP:

Any further written opinion established by the International Preliminary Examining Authority should set forth, as applicable: (A) Any defects in the international application as described in PCT Article 34(4) concerning subject matter which is not required to be examined or which is unclear or inadequately supported;

The further written opinion is prepared on Form PCT/IPEA/408 and typically allows a 2-month reply period for the applicant.