Intellectual Property Rights
What is Patent Corporation Treaty?

The Patent Cooperation Treaty (PCT) is an international treaty to facilitate applicants in filing and seeking patent protection in the Contracting States. The applicants are required to be national or resident of the PCT Contracting States for availing this facility.


Presently, PCT has 153 contracting states. India is also party to the PCT since 7 December 1998.

What is the PCT International Application?

The application filed under PCT by the applicant from contracting state is called as a PCT International Application. The deadline for filing the PCT International Application is 12 months from the earliest priority date. Such an application can be filed with the Receiving Office (RO), which is the national Patent Office of the Contracting State of which the applicant is a national/resident or directly with the International Bureau (IB) (in case national security/defense provision permits).

What are the advantages of filing a PCT International Application?

The advantages of filing a PCT International Application through the PCT System are as follows:

  • time limit to enter the designated national Patent Offices is deferred to 30 or 31 months from the date of earliest priority, which gives extended time to the applicant for identifying potential markets and strategizing, accordingly;
  • the International Search Report (ISR) and Written Opinion provides the scope of the invention in terms of patentability;
  • the opportunity provided to rebut the ISR and Written Opinion by way of informal comments or amendment in the claims or complete specification;
  • the necessary documents such as priority documents submitted during the international phase are not required to be filed with each national patent office along with the national phase application, thus saving extra costs;
  • interest in licensing out the technology can be indicated in the application, which provides effective means to know the parties which are interested in potential technology licensees.
What is the national phase and national phase application?

The PCT international phase is followed by the national phase. The applicant can enter the national phase by filing a PCT national phase application with the national Patent Offices, which were designated in the PCT International Application while filing the International Phase.


The national phase can be entered within 30 or 31 months (depending on the national statute), from the earliest filing date.

Does, the Indian Patent Office acts as a Receiving Office?

Yes, the Indian Patent Office (Delhi Branch) acts as a Receiving Office.

What is the acceptable language for filing the PCT International Application?

The Receiving Office, India (RO/IN) accepts International Applications in English and Hindi language.


Other acceptable languages by various Receiving Offices is Arabic, Chinese, English, French, German, Japanese, Korean, Portuguese, Russian and Spanish.

What is the International Search Report and Written Opinion?

While filing a PCT International Application, the applicant has to designate a competent International Searching Authority (ISA) for conducting a search on the invention disclosed in the International Application. Based on the search conducted, the ISA provides an International Search Report (ISR) and a Written Opinion (WO).

What is the International Preliminary Examination Report on Patentability (IPERP)?

The applicant has to file a Demand (with or without amendment in the specification) with the competent International Preliminary Examining Authority (IPEA) for the international preliminary examination of the PCT International Application. The IPEA conducts a search and provides a patentability analysis, as International Preliminary Examination Report (IPER) along with a Written Opinion.

What is the international publication of an application?

The International Application filed with the IB or RO publishes within 18 months from the earliest priority date.

Can a PCT International Application be assigned?

Yes, rights and interests in the PCT International Application can be assigned by filing a request with the IB. Upon recordal of details, IB issues a notice in this regard. It is recommended to provide documentary evidence in this regard, however the same is not mandatory as per PCT Regulations.

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