The Patent Cooperation Treaty (PCT) is an international patent law treaty among the Paris Convention Countries administered by the World Intellectual Property Organization (WIPO). The PCT makes it possible to seek patent protection for an invention simultaneously in each of a large number of countries by filing a single "international" patent application instead of filing several separate national or regional patent applications. A patent application filed under the PCT is called an international application or a PCT application. The PCT system facilitates filing of patent applications under a single umbrella and provides for simplified procedure for the search and examination of such applications. This allows a resident or national of a PCT member state to obtain the effect of patent filings in any or all of the PCT countries and to defer the bulk of the filing costs usually due on filing. India became a PCT contracting state on December 7, 1998.

Under the PCT system, a single filing of an international application is made with a Receiving Office (RO) in one language paying one set of fees. At least one applicant (physical or legal person) must be a national or resident of a contracting state of the PCT. If there are several applicants named in the international application, only one of them needs to comply with this requirement. This is followed by a search performed by the International Searching Authority (ISA) to find the most relevant prior art documents regarding the claimed subject matter. The search results in an International Search Report (ISR) together with a written opinion on patentability.

International Search Report:

The international search report consists mainly of a listing of references to published patent documents and technical journal articles which might affect the patentability of the invention disclosed in the international application. The report contains indications for each of the documents listed as to their possible relevance to the critical patentability questions of novelty and inventive step (non-obviousness). Together with the search report, the ISA prepares a written opinion on patentability, which will give you a detailed analysis of the potential patentability of your invention. The international search report and the written opinion are to be communicated by the ISA to you by the fourth or fifth month after the filing of the international patent application.

For every international application, the ISA will establish, at the same time that it establishes the international search report, a preliminary and non-binding opinion on whether the invention appears to meet the patentability criteria in light of the search report results. That opinion is sent to you and to WIPO together with the international search report. The written Opinion helps you understand and interpret the results of the search report with specific reference to the text of your international application, being of special help to you in evaluating your chances of obtaining a patent without incurring the additional cost of international preliminary examination.

Applicants can, if they wish, submit informal comments to WIPO in response to this written opinion; in this way, they have an opportunity to respond to the reasoning and conclusions of the written opinion even if they do not plan to take advantage of international preliminary examination). If you do not request international preliminary examination, the written opinion of the ISA will form the basis of the international preliminary report on patentability (IPRP (Chapter I)) which will be communicated by the International Bureau to all PCT Contracting State patent Offices which request it, together with any informal comments submitted. However, if you request
international preliminary examination, the written opinion of the ISA will, in general, be used by the International Preliminary Examining Authority (IPEA) as its own first written opinion, unless the IPEA notifies WIPO to the contrary.

The content of the IPRP (Chapter I) will also be very useful for patent Offices in deciding whether or not to grant the patent in the national phase, especially for those Offices which do not carry out significant substantive examination. This report is made available to the public after the expiration of 30 months from the priority date.

The report enables you to evaluate your chances of obtaining patents in PCT Contracting States. An international search report which is favorable, that is, in which the documents cited would appear not to prevent the grant of a patent, assists you in the further processing of your application in those countries in which you wish to obtain protection. If a search report is unfavorable (for example, if it lists documents which challenge the novelty and/or inventive step of your invention), you have the opportunity to amend the claims in your international patent application (to better distinguish your invention from those documents), and have them published, or to withdraw the application before it is published. The high quality of the international search assures you that any patent granted from an international application is less likely to be successfully challenged, and thus provides valuable input in support of investment decisions.

As a rule, an international search is carried out for all international applications. There are instances, however, where the ISA will not be able to carry out a search. For example, where the international application relates to subject matter which the ISA is not required to search or if the description, claims or drawings are not sufficiently clear for it to carry out a meaningful search. In such cases, the ISA will issue a declaration that no international search report will be issued. There are also circumstances where the ISA will issue a partial search report. This can occur when, in the view of the ISA, the international application contains multiple inventions but the applicant has not paid additional search fees to cover the work required to search those additional invention(s).

On filing of the international application, all contracting states are automatically designated. Subject to reservations made by any contracting state, an international patent application fulfilling the requirements of the treaty and accorded an international filing date, has the effect of a regular national application in each designated state as of the international filing date, which date is considered to be the actual filing date in each designated State. However, in some countries, the prior effect of an international application filed outside such countries may be different from the prior effect of a local national application. For example, in the United States, an international patent application filed outside the United State, has a different prior art effect than a direct US application.

Supplementary International Search:

In addition to the compulsory international search, optional supplementary searches may be carried out by participating international search authorities upon request by the applicant and payment of corresponding fees.

Supplementary international search permits the applicant to request, in addition to the international search (the "main international search"), one or more supplementary international searches each to be carried out by an International Searching Authority other than the International Searching Authority which carries out the main international search.
The supplementary international search report is generally similar in content and appearance to the main international search report; it contains a listing of references to patent documents and other technical literature which may affect the patentability of the invention claimed in the international application. However, it does not repeat documents which have already been cited in the international search report, unless this is necessary because of new relevance when read in conjunction with other documents discovered during the supplementary international search. On occasion, the supplementary international search report may contain more detailed explanations than those in the main international search report. This is due to the fact that, unlike the main international search, no written opinion is established with the supplementary international search report, and these additional details are helpful for a full understanding of the references listed.

The supplementary international search report reduces the risk of new patent documents and other technical literature being discovered in the national phase because it may enlarge the linguistic and technical scope of the documentation searched.

This is also optionally followed by a preliminary examination performed by an International Preliminary Examining Authority (IPEA), after international publication, usually on an amended version of the application.

International Preliminary Examination:

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. If you wish to make amendments to your international application in order to overcome documents identified in the search report and conclusions made in the written opinion of the ISA, international preliminary examination provides the only possibility to actively participate in the examination process and potentially influence the findings of the examiner before entering the national phase – you can submit amendments and arguments, and are entitled to an interview with the examiner. At the end of the procedure, an international preliminary report on patentability (IPRP) will be issued. The International Preliminary Examining Authorities (IPEAs) which carry out the international preliminary examination are the International Searching Authorities mentioned above. For a given PCT application, there may be one or more competent IPEAs; your receiving Office can supply details or you may consult the PCT Applicant's Guide and the PCT Newsletter.

The IPRP which is provided to you, with copies also being sent to WIPO and by WIPO on to the patent Offices of the Contracting States which request it, consists of an opinion on the compliance with the international patentability criteria of each of the claims which have been searched. It provides you with an even stronger basis on which to evaluate your chances of obtaining patents, and, if the report is favorable, a stronger basis on which to continue with your application before the national and regional patent Offices. The decision on the granting of a patent remains the responsibility of each of the national or regional Offices in which you enter the national phase; the international preliminary examination report should be considered by the Offices but is not binding on them.

A PCT application does not itself result in the grant of a patent since there is no such thing as "International Patent". The grant of patent is a prerogative of each national or regional authority. A PCT application, which establishes a filing date in all contracting states, must be followed up with the step of entering into national or regional phases in order to proceed towards grant of one or more patents. If your international complies with the minimum requirements for obtaining an international filing date, it has the effect of a national patent application and certain regional patent applications in all PCT contracting states. The PCT procedure leads to a standard national or regional patent application which may be granted or rejected according to applicable laws in each jurisdiction in which a patent is desired.

Electronic filing of PCT applications:

PCT applications can be filed electronically with receiving Offices which accept such filings. Full electronic filing is possible with the PCT receiving Office at WIPO, and certain national and regional Offices. WIPO's electronic filing software, PCT-SAFE ("Secure Applications Filed Electronically"), which can be downloaded from the PCT website or obtained free of charge on CD-ROM, helps PCT applicants to prepare their international applications in electronic form and to file them either via secure on-line transmission or on electronic media such as diskette, CD-R or DVD-R. While the data about the application is being entered, the PCT-SAFE software validates the entered data and draws the applicant's attention to incorrectly or inconsistently completed parts. It is possible to attach the application text and drawings in XML (extensible Markup Language) as well as in other electronic formats, such as PDF or TIFF format (the file formats available depend on the receiving Office selected). Applicants who file electronically are entitled to certain PCT fee reductions – the highest reductions are applicable when the filing format is XML. More details about PCT electronic filing can be found at

Reductions in respect of fees are available to all applicants who file electronically, based on the type of filing and the format of the application submitted. In addition, an applicant who is a natural person and who is a national of and resides in a State, the per capita national income of which is below 3,000 US dollars, is entitled to a reduction of 90% of certain fees, including the international filing fee. ( For applicability of 90% Reduction in respect of PCT Fees please refer to

Costs of filing and processing of PCT applications:

PCT applicants generally pay three types of fees when they file their international applications: an international filing fee of 1,330 Swiss francs2 (the equivalent of approximately 1,450 US dollars 2 depending on the applicable exchange rate), a search fee which can vary from approximately 410 to 2,400 US dollars2 depending on the International Searching Authority chosen, and a small transmittal fee which varies depending on the receiving Office. Because an international patent application is effective in all PCT Contracting States, you do not incur, at this stage in the procedure, the costs that would arise if you prepared and filed separate applications for all of those States; you have to pay only a
single set of fees for filing the international patent application with the PCT receiving Office. These fees cover the filing, searching and publication of the international patent application, and are payable in the currency, or one of the currencies, accepted by the receiving Office. Further information about PCT fees can be obtained from the receiving Offices, the PCT Fee Tables (, the PCT Applicant's Guide and the PCT Newsletter.

Claiming of Priority of earlier application filed:

Generally, patent applicants who wish to protect their invention in more than one country first file a national or regional patent application with their national or regional patent Office, and within 12 months from the filing date of that first application (a time limit set in the Paris Convention for the Protection of Industrial Property), they file their international application under the PCT. Thus, in an international patent application, you may claim the priority, under the Paris Convention – and to a certain extent within the framework of the World Trade Organization –, of one or more earlier patent applications for the same invention, whether they were national, regional or international applications, for up to 12 months after the filing of the earliest of those applications. If you do not claim priority of an earlier application, the priority date for the purposes of the PCT procedure will be the international filing date of the international application. During the PCT procedure, priority claims may be added and
corrected, within certain time limits.

Languages in which an international patent application can be filed:

In general, an international patent application can be filed in any language which the receiving Office accepts. If you file your application in a language which is not accepted by the International Searching Authority that is to carry out the international search, you will be required to furnish a translation of the application for the purposes of international search. Receiving Offices are, however, obliged to accept filings in at least one language which is both a language accepted by the competent International Searching Authority that is to carry out the international search and a "publication language", that is, one of the languages in which international patent applications are published (Arabic, Chinese, English, French, German, Japanese, Korean, Portuguese, Russian and Spanish). You therefore always have the option of filing your international patent application in at least one language from which no translation is required for either PCT international search or publication purposes.

International Publication:

WIPO publishes the international application shortly after the expiration of 18 months from The priority date (if it has not been withdrawn earlier), together with the international search report. PCT international applications are published online on PATENTSCOPE (, a powerful, fully searchable database with flexible, multilingual interfaces and specific translation tools to assist users and the public in understanding the content of published applications.

National Phase:

Finally, after 30 months from the filing date of the international application, or from the earliest priority date of the application, if a priority is claimed, the international phase ends and the international application enters the regional phase. However, any national law may fix time limits which expire late than 30 months. For example, it is possible to enter the European regional phase at 30 months from the earliest priority date. National and regional phases can also be started earlier, on the express request of the applicant, even before publication of the international application. If the entry into national or regional phase is not performed within the prescribed time limit, the international application generally ceases to have the effect of a national or regional application.

It is only after you have decided whether, and in respect of which States, you wish to proceed further with your international application that you must fulfill the requirements for entry into the national phase. These requirements include paying national fees and, in some cases, filing translations of the application. These steps must be taken, in relation to the majority of PCT Contracting States' patent Offices, before the end of the 30th month from the priority date. There may also be other requirements in connection with the entry into the national phase – for example, the appointment of local agents. More information on national phase entry in general can be found in the PCT Applicant's Guide, and specific information concerning fees and national requirements can be found in the national chapters for each PCT Contracting State in the same Guide.

Once you have entered the national phase, the national or regional patent Offices concerned begin the process of determining whether they will grant you a patent. Any examination these Offices may undertake should be made easier by the PCT international search report and the written opinion, which enable you to make necessary amendments to the claims in the application even before the national procedure starts. It is facilitated even more by the international preliminary examination procedure during which further amendments (and their patentability evaluation) are possible.

Advantages of the Patent Cooperation Treaty:

The procedure under the PCT has many advantages for the applicant, for the patent offices and for the general public which may be summarized as follows:

For the applicant:

1. You have up to 18 months more than if you had not used the PCT to reflect on the desirability of seeking protection in foreign countries, to appoint local patent agents in each foreign country, to prepare the necessary translations and to pay the national fees;
2. If your international application is in the form prescribed by the PCT, it cannot be rejected on formal grounds by any PCT contracting state patent office during the national phase of the processing of the application.
3. The international search report and written opinion contain important information about the potential patentability of your invention, providing a strong basis for you to make business decisions about how to proceed.
4. You have the possibility during the optional international preliminary examination to amend the international application, enter into dialogue with the examiner to fully argue your case and put the application in order before processing by the various national patent offices.
5. You may be able to fast-track examination procedures in the national phase in contracting states that have PCT-Patent Prosecution Highway agreements with the offices which act as ISAs (see .
6. for you as an applicant, international publication online puts the world on notice of your application. You may also highlight your interest in concluding licensing agreements on PATENTSCOPE, which can be an effective means of advertising and looking for potential licensees; and also achieve other savings in communications, postage and translations because the work done during the international processing is generally not repeated before each Office (for example, you submit only one copy of the priority document instead of having to submit several copies).

For the Patent Offices:

The search and examination work of patent Offices in the national phase can be considerably reduced or eliminated thanks to the international search report, the written opinion and, where applicable, the international preliminary report on patentability that accompany the international application.

For the general public:

since each international application is published together with an international search report, third parties are in a better position to formulate a well-founded opinion about the potential patentability of the claimed invention.

Ultimately, the PCT:

brings the world within reach;
• postpones the major costs associated with international patent protection;
• provides a strong basis for patenting decisions; and is used by the world's major corporations, research institutions and universities when they seek international patent protection.

*Taken directly from:


Advocates, Patent & Trademark Attorneys
EF7-10, Vasanth Nagar, Palarivattom
Cochin-682 025, INDIA
Tel:+91484 2337856 / 6457856
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