Before understanding PCT, it is important to be aware of the pre- PCT systems of Invention related protection and their drawbacks.


Earlier system of invention protection required multiple formalities namely:


Multiple search, publication, examination and prosecution, translation and national fees within 12 months all of which were not strategically viable but proving very expensive in the long run draining on the applicant’s resources.


The said issues were discussed in the Washington Diplomatic Conference in 1970 on the Patent Co-operation Treaty which came into effect on January 24th 1978 with 18 contracting states of Paris Convention. Membership to PCT is open to all the signatories of Paris Convention for the protection of Industrial Property.




It is to be borne in mind that the PCT system is only a patent filing system and not a patent granting system. Patent grants are territorial based on the national laws of each of the contracting signatory states. On comparison it is evident that the PCT system does not work like either the Madrid System of International Trademark Protection and the Hague Agreement on Industrial Designs protection.


For global patents protection, applicants have to file or apply to the National Offices of selected countries where the applicants wish to protect their inventions. Decisions regarding patent grants are taken exclusively by the national offices or regional offices such as ARIPO, OAIP, EURASIAN PATENT OFFICE, EUROPEAN PATENT CONVENTION OFFICE.


WIPO is the governing body which administers, co-ordinates and oversees the PCT system.




Any national or resident of the PCT signatory states are entitled to file an international patent application under the PCT system. In case there are multiple applicants, only one of them need to comply with this requirements.


Applicants may file the PCT applications either at their national patent office or with WIPO, Or head offices of the regional patent offices of ARIPO, OAIP, EURASIAN PATENT OFFICE, EUROPEAN PATENT CONVENTION OFFICE which act as receiving offices.


Upon filing the patent application at the receiving offices, applicants have to move the application within 12 months with the WIPO by paying transmittal fees to convert the application into an international application under the PCT.


Transmittals take place in any one of the designated languages which are Arabic, Chinese, English, French, Japanese, Korean, Portuguese, Russian and Spanish. If the applications are not in any of these languages, applicants have to furnish translations to WIPO.


The period of 12 months to convert the national application into an international application is provided, so as to enable applicants to claim priority from the date of filing of the application with the receiving offices. This time limit was set by the Paris Convention and the World Trade Organisation.


The applicant may proceed as under:

-18 months from the date of conversion of the application from national to international application – International Filing Date OR

– 30 or 31 month (based on national patent office) from the date of filing of the application at the receiving offices – Priority Date


To enter the ‘National Phase’ to pursue the patent application with the national office of choice, wherein the applicant wishes to work his patent commercially.


This period from 18 to 30 / 31 months facilitates the applicant in evaluating the viability and commercialisation of his patent before finalising the country of choice.


However, the applicant need not wait until the expiry of 30 / 31 months to begin the national phase entry, he may if he wishes begin the national phase entry any time before the expiry.


Many countries require and mandate incidental procedures such as translations, legalisation of certain documents etc., therefore, to avoid last minute inconveniences, applicant should strategise their national phase entry 6 months in advance. This affords ample time to comply with the requirements of the respective national offices.



1. Filing the International Application in compliance with PCT formalities requirements in one of the designated languages along with one set of fees.

2. Identification of published documents and Prior Art through International Search by an International Searching Authority (ISA).

3. All international applications are to be subjected to international search by way of a request from the applicant. International search is aimed at discovering relevant prior art. International search is based on claims, description and drawings, published patent documents and technical journal articles.

4. Once the search report is put in place, a detailed analysis of the patentability of the invention is prepared by way of a written opinion by the ISA on novelty and inventive step that is non-obvious. This written opinion is non-binding. The search report and the written opinion are communicated to the applicant by the ISA within 4/5 months from the filing of the international patent application.

5. The international search report is a valuable tool for the applicant as it helps the applicant evaluate chances of obtaining patents in the contracting states.

  • A favourable search report strengthens the chances of obtaining patents
  • An unfavourable search report may be used to amend claims to overcome the lacunae so that the application encounters least resistance at the national office.
  • Applicant may withdraw applications before publications based on the search report which will help them preserve the invention.
  • Applicants based on the search report save considerable money before proceeding with registration formalities.

6. International search could produce a complete search report or a partial search report. Partial search reports are issued when international application contains multiple inventions but the applicant would not have paid sufficient fee to cover search for those additional inventions.

7. International search report has the following role to play: – Applicants may furnish comments to the written opinion of the ISA. These comments are informal in nature. – The responses by the applicants to the reasonings and conclusions reflected on the written opinion will together be considered by the ISA while establishing the International Preliminary Report on Patentability (IPRP). – The IPRP is communicated by the IB to all the patent offices of the contracting states. – The IPRP is used by the patent offices in deciding on whether or not to grant patents to the applicant in the national phase. – The IPRP is made available to the public after the expiry of 30 from the priority date.

8. Supplementary International Search Report: applicant may request a supplementary international search in addition to the international search (the main international search). One or more such supplementary international searches each to be carried out by an ISA other than the ISA which carried out the main international search may be requested. The supplementary search report enlarges the linguistic and technical scope of the documentation searched which facilitates in reviewing the invention, claims etc.



WIPO publishes the international application promptly after the expiry of 18 months from the date of priority along with the main search report.


Until 18 months that the international publication takes place, the international patent application is not accessible to third parties unless the applicant so requests or authorises such parties. After the expiry of 18 months, third parties can access the application .


In the event applicants withdraw the application before international publication, the international publication does not take place hence denying access to third parties.




International Preliminary Examination is a second evaluation of the potential patentability of the invention using the same standards on which the written opinion of the ISA was based.


International Preliminary Examination is the only window of opportunity available for the applicant before beginning the national phase entry to furnish amendments and arguments in order to overcome the objections per the written opinion of the ISA. Applicants may also request an interview / hearing with the examiner.


The outcome of the procedure will produce an International Preliminary Report on Patentability (IPRP Chapter II) which will be issued to the applicants and WIPO and through WIPO to the patent offices of the contracting states.


This report is consulted by the national patent offices with whom the discretion of granting patents lie. However, the report is not binding on the national offices.




Once the applicant decides on the states in which the patent is to be protected, the applicant has to then comply with the requirements as notified by the respective national law to undertake national phase entry into those chosen contracting states.


These steps for compliance must be fulfilled on or before 30 / 31 months from the priority date based on the respective national law of the contracting states.


However, applicants must ensure that they are well within time to complete these formality requirements else they run the risk of losing priority on their inventions.



The PCT procedure has proved to be immensely beneficial to applicants from a large strata of society comprising of sole inventors to large R&D conglomerates, from students to universities and small & medium businesses to multinational companies.


Proper awareness and understanding of this efficient and smooth patenting system has ensured timely commercialisation of a plethora of inventions that have impacted society in reaping a multitude of benefits.


Our Attorneys are well placed in assisting you with the usage of PCT system so that you gain the maximum benefit out of your inventions. You may visit our country-wise content on this website to gain an insight into national patent laws for an all-round benefit.

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