Patent Registration Process under Patent Cooperation Treaty (PCT)

With a massive increase in filing of international applications, clients have been constantly asking queries pertaining to patent registration process under Patent Cooperation Treaty (PCT). This article is a quick reference for an overview of procedure for filing an application under PCT route.

For filing a patent application in several countries an Applicant can either directly file separate patent applications at the same in countries he/she seeks protection or choose to file under Paris Convention or choose to file under Patent Cooperation Treaty. Under Paris Convention if patent application is filed in a Paris Convention Contracting State, a separate patent application can be filed in other Paris Convention Contracting States within 12 months from the filing date of the patent application and claiming priority from the patent application.

Conversely, under PCT, a patent application can be filed either directly or within 12 months from date of filing of the patent application in a PCT Contracting State, and claiming priority from it.

PCT is an international patent law treaty, concluded in 1970 that provides a unified procedure for filing patent applications under 152 Contracting States. A patent application filed under PCT route is called an International Application or a PCT application. The PCT filing procedure includes the following:


If an Applicant is a resident of PCT Contracting State, he/she can file a PCT application in a “receiving office” that can be a competent national or a regional patent office, or an International Bureau (IB) of World Intellectual Property Organization (WIPO). The international application should be filed in a receiving office either directly or within 12 months from the filing date of the application in a PCT Contracting State. The application can be filed in any language accepted by the receiving office.

Issuance of International Search Report (ISR) and Written Opinion

International Searching Authority (ISA) is determined by the receiving office where the international application is filed. Also, Applicant can choose an ISA if the receiving office provides a choice of more than one competent ISA. If the application is filed in a language which is not accepted by the ISA that is to conduct an international search, the Applicant needs to furnish a translation of the application for purposes of international search.

The ISA conducts an international search of relevant patent documents and other technical literature. Based on the search results, ISA publishes an International Search Report (ISR) consisting of listing of references to published patent documents and technical journal articles pertaining to patentability of the invention disclosed in the international application. Along with search report, ISA also prepares a written opinion on patentability of the invention disclosed in the international application. The Applicant may receive an ISR within 16 months from date of priority.

International Publication

After the expiration of 18 months from the priority date, WIPO publishes the patent application along with the ISR and written opinion on PATENTSCOPE. Thus, a third party can now access the patent application.

National Phase

Various Contracting States provide a timeline of 30 or 31 months from date of the priority to enter in National phase. After an Applicant has decided the Contracting States in which he/she requires to proceed with the international application, he/she can file for entry into national phase of the Contracting States. Filing requirements can include paying of national fees, filing translations of the application and/or appointment of local agents. After entering into national phase, the national or regional patent office processes the international application as per national laws pertaining to patents in that country.

Following flow chart represents registration process of an international application under PCT:


About the Author: Ms. Prigya Arora, Patent Associate at Khurana & Khurana, Advocates and IP Attorneys. Can be reached at

Leave a Reply

Your email address will not be published. Required fields are marked *


5 × 3 =