PCT – Understanding Chapter I and Chapter II
Chapter I vs Chapter II in PCT Applications: What’s the Key Difference?
Under the Patent Cooperation Treaty (PCT) system, all international applications go through an international search and receive a written opinion from the examiner. But what happens next depends on whether the applicant stays under Chapter I or opts into Chapter II.
Chapter I: Examination Without Interaction
By default, every PCT application proceeds under Chapter I. In this path, the International Searching Authority (ISA) issues the International Search Report (ISR) along with a Written Opinion on the potential patentability of the invention. At this stage, there is no direct interaction between the applicant and the examiner.
The applicant does have the opportunity to file amendments under Article 19 after receiving the ISR and Written Opinion. This option remains available until the later of 16 months from the priority date or two months from the date of transmittal of the report and opinion. However, these amendments are not reviewed by the ISA during the international phase; instead, they are simply published and taken into account by national or regional patent offices during the national phase.
Chapter I is often chosen by applicants who want a quick assessment of their invention or who plan to address any issues directly during the national phase.
Chapter II: Examination With Dialogue
If the applicant wants to engage with the examiner, they can file a Demand for International Preliminary Examination, triggering Chapter II. This option allows the applicant to respond to the written opinion, submit amendments, and participate in a dialogue with the examiner to clarify or defend the invention.
The result of this interaction is the International Preliminary Report on Patentability (IPRP Chapter II). This report often carries significant weight in national or regional patent offices when deciding whether to grant the patent.
Which One Should You Choose?
- Choose Chapter I if you’re looking for a faster, lower-cost route and are prepared to manage patentability issues at the national stage.
- Choose Chapter II if you are seeking protection in multiple countries and want to strengthen your patent position before entering the national phases. This route allows you to benefit from examiner feedback, providing an opportunity to improve the application in advance—potentially reducing prosecution time and costs during the national phase.
At Patentarea, we guide our clients daily in choosing the right PCT strategy based on their commercial goals, budget, and target markets.
Are you in the PCT process or considering filing one? Let’s talk.