I have an invention. How can I protect it in several countries?

You have a few options. For example:

  1. file separate patent applications at the same time in all of the countries in which you would like to protect your invention (for some countries, regional patents may be available);
  2. file a patent application in a Paris Convention country (one of the Member States of the Paris Convention for the Protection of Industrial Property), and then file separate patent applications in other Paris Convention countries within 12 months from the filing date of that first patent application, giving you the benefit in all those countries of the filing date of the first application;
  3. file an application under the PCT, which is simpler, easier and more cost-effective than either (1) or (2).
What is the Patent Cooperation Treaty (PCT)?

The PCT is an international treaty, administered by the World Intellectual Property Organization (WIPO), between more than 125 Paris Convention countries. 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. The granting of patents remains under the control of the national or regional patent Offices in what is called the “national phase”.

Briefly, an outline of the PCT procedure includes the following steps:

Filing: you file an international application, complying with the PCT formality requirements, in one language, and you pay one set of fees.

International Search: an “International Searching Authority (ISA)” (one of the world’s major patent Offices) identifies the published documents which may have an influence on whether your invention is patentable and establishes an opinion on your invention’s potential patentability. International Publication: as soon as possible after the expiration of 18 months from the earliest filing date, the content of your international application is disclosed to the world. International Preliminary Examination: an “International Preliminary Examining Authority (IPEA)” (one of the world’s major patent Offices), at your request, carries out an additional patentability analysis, usually on an amended version of your application.

National Phase: after the end of the PCT procedure, you start to pursue the grant of your patents directly before the national (or regional) patent Offices of the countries in which you want to obtain them.

What is the effect of an international patent application?

In general terms, your international patent application, provided that it complies with the minimum requirements for obtaining an international filing date (see PCT Article 11), has the effect of a national patent application (and certain regional patent applications) in all PCT Contracting States. An international patent application must be prepared in accordance with certain formal requirements set out in the Treaty and Regulations, which have become international standards effective in all of the PCT Contracting States. If you comply with these requirements, subsequent adaptation to varying national (or regional) formal requirements (and the cost associated therewith) will not be necessary.

How long does the PCT process take?

You have, in most cases, 18 months from the time you file your international patent application (or 30 months from the filing date of the initial patent application of which you claim priority – see Question 10) before you have to begin the national phase procedures with individual patent Offices. This means that you normally have at least 18 additional months before you have to fulfill the national requirements (see Question 23) than if you do not use the PCT.

This additional time can be useful for evaluating the chances of obtaining patents and exploiting your invention commercially in the countries in which you plan to pursue patent protection, and for assessing both the technical value of your invention and the continued need for protection in those countries.

It is important to note, however, that you don’t have to wait for the expiration of 30 months from the earliest filing date of your patent application (“priority date”) before you enter the national phase – you can always request an early entry into the national phase (see PCT Articles 23(2) and 40(2)).

In the national phase, each patent Office is responsible for examining your application in accordance with national or regional patent laws, regulations and practices resulting in, if all things are favorable, the grant of a patent. The time required for the examination and grant of a patent varies across patent Offices.

Can priority of an earlier patent application be claimed?

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 can be added and corrected, within certain time limits.

What is a PCT international search?

A PCT international search is a high quality search of the relevant patent documents and other technical literature in those languages in which most patent applications are filed (that is, English, French and German, and in certain cases, Chinese, Japanese, Russian and Spanish, and from April 1, 2007, Korean). The high quality of the search is assured by the standards prescribed in the PCT for the documentation to be consulted (see PCT Rule 34), and by the qualified staff and uniform search methods of the ISAs, which are all experienced patent Offices. The international search is carried out in accordance with the International Search and Preliminary Examination Guidelines and results in an international search report and a written opinion of the ISA on the potential patentability of your invention.

What is an 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 claimed 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 (see Question 16). 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.

What is the value of the international search report?

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.

What is 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 Chapter II) will be issued. The International Preliminary Examining Authorities (IPEAs) which carry out the international preliminary examination are the International Searching Authorities mentioned above (see Question 12). For a given international patent application, there may be one or more competent IPEAs; your PCT receiving Office can supply details or you may consult the PCT Applicant’s Guide and the PCT Newsletter.

Who uses the PCT?

The PCT is used by the world’s major corporations, research institutions and universities when they seek international patent protection. And it is likewise used by small and medium-sized enterprises and individual inventors. The PCT Newsletter (see www.wipo.int/pct/en/newslett/index.jsp) contains a yearly list of the largest PCT filers.

How do I enter the national phase?

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 Volume II of 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.

What happens to my application in the national phase?

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. You 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).

What are the advantages of the Patent Cooperation Treaty?

The procedure under the PCT has great advantages for you as an applicant, for the patent Offices and for the general public:


  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. you can rest assured that, 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. on the basis of the international search report and the written opinion, you can evaluate with reasonable probability the chances of your invention being patented;

  4. you have the possibility during the optional international preliminary examination to amend the international application and thus put it in order before processing by the various patent Offices;

  5. the search and examination work of patent Offices 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;

  6. 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; and

  7. for you as an applicant, international publication puts the world on notice of your application, which can be an effective means of advertising and looking for potential licensees.

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