Patent Cooperation Treaty Kit

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Overview of the PCT system

Overview of the PCT system that shows PCT International Applications filed with Receiving Offices who transmit applications to the International Bureau (IB), International Searching Authorities (ISA), and International Preliminary Examining Authorities (IPEA), the IB also publishes the PCT International Applications and communicated with Designated Offices which then grant Patents.  A timeline at the bottom shows the time from the Priority Date at 0 months to the end of the international phase at 30 months.

Source : World Intellectual Property Organization (WIPO)

What is the PCT?

The Patent Cooperation Treaty (PCT) is an international treaty administered by the World Intellectual Property Organization (WIPO) that has been ratified by more than 140 countries. Under the PCT system, after an international application is successfully filed, the applicant is able to designate or elect any of the signatory countries to seek patent protection at the national level. The granting of patents remains the responsibility of each national patent office.

What is WIPO?

The World Intellectual Property Office (WIPO) is an agency of the United Nations dedicated to issues dealing with intellectual property. In its role as administrator of the PCT, WIPO is referred to as the International Bureau (IB) and carries out five major processing functions:

  • receipt of the record copy;
  • receipt of amendments to the claims;
  • international publication;
  • communication of the application and International Search Report to designated Offices; and
  • communication of the International Preliminary Report on Patentability (Chapter I or Chapter II) to designated/elected Offices

In addition, WIPO produces various materials that provide information related to patents and the PCT, including:

  • The PCT Applicant's Guide, a comprehensive guide that addresses each step of the PCT filing process, including requirements for national entry into the contracting states.
  • The PCT Gazette, which is published weekly and contains notices and indexes relating to the publication of individual international applications and general information concerning the PCT.
  • The PCT Glossary, which aids in the understanding, drafting or translating of PCT documentation.
  • Access to PATENTSCOPE, a database that houses the PCT applications that have been published and facilitates the search of international patent applications.

The PCT procedure simplified

The PCT procedure consists of two main phases: an international phase and a national phase. The expressions "international phase" and "national phase" are not official PCT terms, but have utility and have become customary references.

International Phase


The applicant files an international application, which complies with the PCT formality requirements, in one language, and pays one set of fees. The application is processed by the Receiving Office (RO) and is accorded an international filing date and an international application number.

Form PCT/RO/101 Request

International Search

An International Searching Authority (ISA) identifies any published documents which may have an influence on whether the invention is patentable in an International Search Report (ISR) and then summarizes the invention's potential patentability in a written opinion.

Publication Of Documentation

Shortly after the expiration of 18 months from the filing date, the content of an international application is published along with the ISR.

Chapter Designation

Should the applicant decide to continue with the application process, they must then choose which course to pursue:

  1. Chapter I of the PCT – This is the default designation. If the applicant chooses to continue, the application will proceed with entry into the national phase. In accordance with Article 19 of the Treaty, after receiving the findings of the ISR, the applicant is entitled to a one-time amendment of the claims. Any amendments must be filed with the International Bureau. The written opinion will serve as the International Preliminary Report on Patentability (IPRP) and will be communicated to the states where patent protection is being sought. The states in which patent protection is being sought are referred to as DESIGNATED states.
  2. Chapter II of the PCT – At the option of the applicant, a PCT/IPEA/401 form (referred to as a demand) is filed with an International Preliminary Examining Authority (IPEA). The filing of a demand should be considered if the applicant is not sure about their chances of obtaining patent protection. The IPEA will conduct an additional patentability analysis (referred to as an International Preliminary Examination Report). In accordance with Article 34 of the Treaty, any part of the specification may be amended and any amendments are transmitted directly to the IPEA , which will analyse the amended version of the application. The report offers a non-binding opinion on whether the invention is novel, involves an inventive step and has industrial applicability. The International Preliminary Examination Report will serve as the International Preliminary Report on Patentability and will be communicated to the states where patent protection is being sought. Theses states are referred to as Elected states.

Commnunication With National Offices

The designated or elected office will request from the International Bureau a copy of the published international application and the International Search Report, as well as the International Preliminary Report on Patentability (Chapter I or Chapter II as required).

National Phase

The applicant can now seek patent protection from the national, in some cases regional, patent offices of the states that have been designated or elected during the application process. Further action is required before and in each of the national (or regional) offices, such as payment of national (or regional) fees, and provision of any translations that are required.

It is important to note that in the national phase, any patent office is free to apply the criteria of its national law to determine patentability. The national offices will examine the international application based on prior art and any other conditions of patentability that do not constitute form or content requirements of the international application.

Each contracting state has provided a detailed summary of the requirements for entry into their national phase. As practices and rules may change, the only authentic sources of information on requirements are the laws, rules and regulations of each state. Patent offices inform applicants of the services provided by registered patent agents. Patent agents have expert knowledge and experience which can be exploited during the preparation and prosecution of patent applications. The CIPO web site,, provides a list of registered patent agents who are entitled to represent applicants before the Canadian Patent Office.

Minimum requirements for filing

You are entitled to file an international patent application if you are a national or resident of one of the PCT Contracting States. If there are several applicants named in the international application, only one of them needs to comply with this requirement. An international patent application must be prepared in accordance with certain formal requirements set out in the Patent Cooperation Treaty and its Regulations. These requirements are presented in WIPO's PCT Applicant's Guide - International Phase. If an applicant complies with these requirements, subsequent adaptation to varying national (or regional) formal requirements will not be necessary.


Standardized forms are used to collect information during the application process. The WIPO PCT forms page offers editable copies of the required PCT forms, as well as samples of properly completed forms.


For the application to be recognized by the International Bureau (WIPO), it must also be accompanied by the requisite fees. All required fees must be paid within one month from the date of receipt of the international application; late payments are subject to an additional fee. Fees to be transmitted include:

  • Transmittal fee - This fee is intended to compensate the RO for the work it must perform in connection with the international application.
  • International filing fee - Fee paid to the RO for the benefit of the International Bureau when filing an international application.
  • Search fee - Fee paid to the RO for benefit of the ISA for carrying out the international search.
  • Preliminary examination fee and handling fee - Fee paid to the IPEA for filing a demand and for conducting an examination of the application.

How to file an international application

Once the international application has been prepared according to PCT requirements, the application should be filed. When filing the international application, the applicant has four options:

1) International Bureau as Receiving Office

An international application may be filed directly with the International Bureau. The IB will act as the Receiving Office; however the ISA and IPEA is determined based on the Contracting State which corresponds to the nationality or country of residence of the applicant. Where two or more applicants are from different Contracting States, filing the international application with the IB may result in a wider choice of authorities. In such a circumstance, the choice of ISA must be indicated in the request and the choice of IPEA must be indicated in the demand.

The IB will receive international applications:

By mail International Bureau of WIPO
PCT Receiving Office Section
34, chemin des Colombettes
1211 Geneva 20
By facsimile (41-22) 910 06 10

Note: Originals of facsimiles need to be received within 14 days of transmittal.

Electronic form:

2) National office as the Receiving Office

An international application may be filed with the national office of the PCT contracting state of which the applicant is a resident or national, or with the office acting for that state. If there are two or more applicants, it is sufficient for at least one of the applicants to satisfy this requirement.

To file the international application with Canada as the RO, please address your applications to the Commissioner of Patents and submit the application to:

By mail or in person Place du Portage I
50 Victoria St., Room C-114
Gatineau, Quebec K1A 0C9
By facsimile 819-953-CIPO (2476)
819-953-OPIC (6742)

Note: Faxes sent to any other number will not be considered received by the office.

Electronic form /eic/site/cipointernet-internetopic.nsf/eng/wr01355.html

Correspondence delivered by electronic means of transmission, including facsimile, will be considered to be received on the day that it is transmitted if delivered and received before midnight, local time at CIPO on a day when CIPO is open for business. When CIPO is closed for business, correspondence delivered on that day will be considered to be received on the next day on which CIPO is open for business.

3) Electronic filing using PCT-SAFE software

PCT-SAFE (Secure Applications Filed Electronically), offers applicants the means to prepare their international applications electronically and to file the application either via secure online transmission or using physical media (e.g., diskette, CD-R, DVD-R). Electronic filing will result in a reduction in certain fees. All this is explained in the general overview and frequently asked questions concerning PCT -SAFE, which are available from the WIPO web site. Please note, there are minimum system requirements to both use and download the PCT-SAFE software.

To file an application, please visit CIPO's PCT E-Filing web page, or WIPO's Electronic Filing (PCT-SAFE) web page.

4) Electronic filing using ePCT online service

a) for PCT applications filed with CIPO in its capacity as Receiving Office

ePCT can be used to prepare, validate and download an e-filing package for subsequent transmittal to CIPO as the Receiving Office. CIPO as a Receiving Office does not accept direct online filings of international applications through the ePCT online service. Once the e-filing package has been prepared with the ePCT online service applicants will need to visit CIPO's PCT E-Filing web page to submit the e-filing package.

b) for PCT applications filed to the International Bureau in its capacity as Receiving Office with CIPO as the designated International Searching Authority.

ePCT can also be used to prepare, validate and file a PCT application with the International Bureau as Receiving Office for subsequent transmittal to CIPO as the International Searching Authority. This process is explained in the Applicant User Guide and frequently asked questions concerning ePCT, which are available from the WIPO ePCT web site.

If the state of nationality and residence of the applicants is CA, then only CA will be available as ISA. However, if there are different states of nationality or residence, you will need to choose the ISA. In any case, you will have to click on the drop down menu to indicate the ISA, as shown below:

International Searching Authority - CA - Canadian Intellectual Property Office

Screenshot from ePCT

The Canadian Intellectual Property Office

The Canadian Intellectual Property Office (CIPO) plays a role at both the international phase and national phase of the PCT system. These roles include:

  • Receiving Office (RO)
  • International Search Authority (ISA)
  • International Preliminary Examining Authority (IPEA)
  • Designated/Elected Office

International Phase

The Patent Office has three distinct roles during the international phase:

(1) Receiving Office

If the applicant, or one applicant from a group of applicants, is a national or resident of Canada, the application may be filed with CIPO. The filing of an application must be in one of Canada's two official languages, either English or French. The transmittal, international filing and search fees must be paid in Canadian currency, and are payable within one month of receipt of the international application. These and further requirements are outlined in WIPO's PCT Guide.

  • Step 1
    CIPO receives the international application from the applicant.
  • Step 2
    CIPO checks the international application to determine whether it meets the prescribed requirements for form and content of international applications. This check is formal in nature only and does not go into the substance of the invention.
  • Step 3
    If the international application meets the PCT requirements for giving the application an international filing date, CIPO accords the international filing date and international application number.
  • Step 4
    CIPO transmits the "record copy" of the international application to the International Bureau, keeps a "search copy" for its roles as an International Searching Authority, and keeps one copy as the "home copy."

(2) International Search Authority (Chapter I)

Where an international application is filed with Canada as the RO, CIPO will serve as the International Search Authority (ISA). Canadian examiners will produce an International Search Report (ISR) and a Written Opinion of the International Search Authority (WO-ISA). The WO-ISA provides the applicant with a preliminary, non-binding opinion on the issues of novelty, inventive step and industrial applicability. This allows the applicant to assess, at the search stage, whether to proceed to the national/regional phase. If no demand for international preliminary examination is filed, the WO-ISA will be converted by the IB into an International Preliminary Report on Patentability (IPRP Chapter I). These and further requirements are outlined in WIPO's PCT Applicant's Guide.

(3) International Preliminary Examining Authority (Chapter II)

CIPO will carry out an International Preliminary Examination on condition that the applicant has filed a "demand" form and paid the accompanying fees. The applicant needs to indicate in the demand if the application is to be examined as originally filed or amended in accordance with Articles of the PCT. The purpose of the International Preliminary Examination under Chapter II is not grant or refusal of a patent, but provision of a preliminary and non-binding opinion on whether the claimed invention appears to be novel, involve an inventive step and have industrial applicability. These and further requirements are outlined in WIPO's PCT Applicant's Guide.

Questions during the International Phase

Prior to filing, general questions about the PCT system, including how to file an international application and the procedure to be followed during the international phase, will be answered by contacting either WIPO or CIPO.

Contact information for WIPO:

(+41-22) 338 83 38
(+41-22) 338 83 39

Note: Telephone opening hours are from 9.00 a.m. to 6.00 p.m. Central European time (from 3.00 a.m. to 12.00 p.m. (noon) Eastern Time).

Contact information for CIPO's Client Service Centre:

Telephone 1-866-997-1936 (toll-free within Canada and the United States)
819-934-0544 (international calls)
Facsimile (819) 953-CIPO (953-2476)
(819) 953-OPIC (953-6742)

If the international application was filed in Canada, CIPO will handle inquires concerning the progress of filed PCT applications, at:

In Writing Canadian Intellectual Property Office
Patent - PCT International
Place du Portage I
50 Victoria Street, Room C-114
Gatineau QC K1A 0C9
By Telephone 1-866-318-9638 (toll free in Canada)
819-997-0868 (for local and international calls)
By E-mail

National phase

If Canada is designated or elected for national protection, there are a few requirements that an applicant needs to fulfill to successfully enter the "national phase" in Canada. One such requirement is that the application must be submitted in one of Canada's two official languages: English or French. Another requirement is that maintenance fees for each one-year period from the international filing date are due at the time of entry into the national phase. Additional requirements are listed in WIPO's PCT Applicant's Guide.

The time limit for entering Canada's national phase is 30 months. Late entry is available, and the time limit may be extended up to 42 months from the earliest priority date provided the applicant pays the national entry fee and the additional late entry fee. Upon national entry, the application is considered a national application and prosecution is carried out in accordance with statutory requirements, the Patent Act and Patent Rules. Copies of these legal texts and additional information are available from the CIPO web site.

All applicants may use the services of a patent agent and benefit from their experience and knowledge in preparing and prosecuting applications before the office. However, where the applicant is not the inventor of the alleged invention, the appointment of a patent agent is required. Once a patent agent has been appointed, CIPO will correspond only with the patent agent concerning the prosecution of the application. Only registered patent agents from CIPO's agent list are able to conduct business before the office.

Acronym List

  • CIPO: Canadian Intellectual Property Office
  • RO: Receiving Office
  • IB: International Bureau
  • IPEA: International Preliminary Examing Authority
  • IPRP: International Preliminary Report on Patentability
  • IPO: International Property Office
  • ISA: International Search Authority
  • ISA: International Search Authority
  • WIPO: World Intellectual Property Office
  • WO-ISA: Written Opinion of the International Search Authority

Summary of Links

This list of useful links has been compiled to facilitate the understanding of the international filing system.

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