International Preliminary Examination (IPE)

The international preliminary examination (often referred to as “Chapter  II”) is an optional part of the processing of an international patent application.

The Process of IPE

After receiving the ISA’s written opinion, applicants can request an optional international preliminary examination. It is a second evaluation of the invention’s patentability carried out by an IPEA, usually on an amended version of the application (all ISAs are also IPEAs). The resulting international preliminary report on patentability further assists the applicant in determining whether to enter the national phase.

The aim of the international preliminary examination is not to grant or refuse a patent, but to obtain a preliminary and non-binding opinion as to whether the claimed invention appears to be novel, to involve an inventive step and to be industrially applicable.

A secondary objective is to identify whether there appear to be any defects in the form or contents of the international application, for example with regard to the clarity of the claims, the description and the drawings, or whether the claims are fully supported by the description.

Time limit for filing the demand

The applicant shall file the demand with the competent International Preliminary Examining Authority before the expiration of the later of the following time limits:

  1. three months from the date of transmittal to the applicant of the international search report and written opinion established under Rule 43bis.1, or of the declaration referred to in Article 17(2)(a); or
  2. 22 months from the priority date of the international application.

The appropriate fees, i.e. a handling fee and a preliminary examination fee, shall be paid simultaneously with the filing of the demand to the IPEA.

Time limits and Delivery

The Visegrad Patent Institute will issue an international preliminary report on patentability within at least 28 months from the priority date unless there is

  • late submission of requested documents (demand, amendments, etc.) 
  • non-compliance with time limits concerned with IPEA invitations (of non- or late payment of fees, late furnishing of translations, corrections of obvious errors, etc.) 


Fees relating to PCT Chapter  II must be paid directly to the IPEA. See the current schedule fees.