PCT Explanation



PCT Offers Common Procedures. The PCT specifies common procedures carried out first on all international applications during the international phase of processing under the PCT. The formalities check, the international search and (optionally) the international preliminary examination carried out during the international phase. These formalities give the applicant more time and a better basis for deciding whether and in what countries to further pursue the application.


LAYOUT. The PCT is a complex subject are that requires more than one page of explanation.  The PCT discussion is on 5 web pages:

  • pct — explains what the PCT process is and some reasons for filing. 
  • pctexplain — explains how the PCT process works. You are on this page now.
  • pctstrategy — explains potential PCT filing strategies to consider.
  • pctcosts — explains the costs of various PCT filings.
  • pctnat — explains the U.S. National Stage of the PCT process.

Four Steps in Phase I. The international phase consists of four main steps of which the first three occur automatically and the last is optional:

  1. Filing. The applicant files the international application in the “Receiving Office.”
  2. Search. The applicable “International Searching Authority” produces an international search report and written opinion on patentability.
  3. Publication. The International Bureau of WIPO publishes the international application together with the international search report and sends the application to the designated national offices for further processing. And,
  4. Preliminary Examination. The applicant decides whether or not to request (“demand”) an international preliminary examination before the later of (1) three months from the date of transmittal to the applicant of the international search report (or the declaration that no International Search Report will be established); or (2) 22 months from the priority date. For all countries but three, the demand must be filed within 30 or 31 months of the priority date.  The U.S. limit is 30 months.
    A demand for a preliminary examination essentially asks for the preparation of an international preliminary examination report on patentability by one of the “International Preliminary Examining Authorities.” The international preliminary report on patentability analyzes aspects of the general patentability of the invention.

Who may be appointed as my attorney? An attorney or agent may be appointed to prepare and file your application in the international phase when that attorney or agent has the right to practice before the Office with which the international application will be filed. Generally, an international application is filed in a Contracting State of which any of the applicants is a resident or a national.  This is specified in section 19.1 of the Patent Cooperation Treaty.

Phase II (National Phase). On completion of the international phase, further action is required before and in each of the national (or regional) Office that the applicant wishes to grant him a patent on the basis of his international application. In particular, the applicant has to pay each such Office the required national (or regional) fees, furnish them with any translations that are required and appoint a representative (patent agent) where required. There are time limits by which those steps must be taken if the application is to proceed in the national phase. If the steps are not taken within the applicable time limit, the effect of the international application may cease in any State where the time limit has not been met.

Deadline Dates. As of April 1, 2002, the national stage requirements are due not later than at the expiration of 30 or 31 months from the priority date even if no demand for preliminary examination has been filed. Previously, one had to file a demand for a preliminary examination before the expiration of 19 months from the priority date in order to extend the national phase to 30 months (31-months for some countries or regions). This 19 month filing is no longer required.

Three countries (Luxembourg, United Republic of Tanzania, and Uganda) currently do not honor the 30 or 31-month time limit for national applications. However, they will honor it if the applicant chooses a regional designation to which they are a party, which specify a 31-month time limit. These regional patenting authority is the African Regional Industrial Property Association. Coverage by the regional authority enables applicants to enter the regional phase (as distinct from the national phase) in those States within the time limit of 31 months. If an applicant wants only a national patent in one of these 3 countries, then the applicant must file the national stage application within 19 months from the priority date or file a demand for preliminary examination within that period.  WIPO offers a download of a web page listing each country’s national stage deadline.

While the minimum deadline dates are mandatory, countries may have longer periods in national laws. It is easy, even for professionals, to make a mistake on deadline dates for the PCT. Be very careful and be sure to consult an attorney on them. See the Frequently Asked Questions page for an example.

The national (or regional) patent offices then examine the application and grant or refuse the national (or regional) patent on the basis of their controlling national laws.

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