Patent Cooperation Treaty

The Patent Cooperation Treaty

By: Joel Douglas, Eric Merenstein

The Patent Cooperation Treaty (PCT) is an international patent law treaty with over 150 contracting states. The PCT provides a procedure that enables at least one applicant to apply for patent protection for an invention in one or more of the contracting states on the basis of a single PCT patent application covering the invention (also referred to as an international patent application).

The PCT application can either be filed as a first patent application, or can claim priority to a patent application previously filed in another jurisdiction (e.g., a non-provisional patent application or a provisional patent application). An applicant generally has 12 months from the effective filing date of an earlier filed patent application to file a patent application (PCT or otherwise*) claiming priority to the earlier filed patent application.

The PCT procedure can be broken down into phases (or stages). The first phase is referred to as the international phase, and the second phase is referred to as the national phase.

During the international phase, the PCT application is filed with a patent office competent to receive the PCT application, referred to as a Receiving Office (RO). The PCT application will also designate a International Search Authority (ISA). As part of the international phase, the ISA performs a search to identify any relevant prior art, and will generate a non-binding international search report (ISR) and written opinion (WO) (ISR-WO) based in part on the search results. There are ways during the international phase for an applicant to make amendments and/or request additional examination, which are beyond the scope of this article.

Each contracting state has a national phase deadline by which an applicant can choose to enter the national phase for the contracting state. The typical national phase deadline is 30 months from the priority date of the PCT application. However, some contracting states have national phase entry deadlines less than or greater than 30 months. An applicant can enter the national phase of a contracting state at any time prior to its national phase entry deadline.

A simplified PCT timeline in which a priority application is filed before a PCT application is shown in Figure 1, where the numbers represent number of months relative to the priority application filing date:


Figure 1

The following are some of the potential benefits of filing a PCT application:

  1. Cost reduction. For example, the PCT application eliminates the need to file direct patent applications in multiple individual jurisdictions. The ISR-WO can help an applicant determine whether to cut their losses before investing additional money pursuing national phase entries. The ISR-WO can also help guide an applicant to amend a patent application before making national phase entries, which can reduce downstream prosecution costs.
  2. Buys additional time. As mentioned above, most contracting states give applicants about 30 months from the priority date of the PCT application to file patent applications in other jurisdictions. This is an additional 18 months as compared to what an applicant would be entitled to via direct patent filings. This additional time can be used to decide if and where to file additional patent applications, market and test the product, raise funds to go through with national phase entry, and defer costs.

*                  National phase can also be entered through Paris Convention, an international patent law treaty that predates PCT.

If you need assistance with filing a PCT application, or any other type of patent application, please visit us at to find a qualified patent practitioner.

Joel DouglasJoel Douglas is a licensed U.S. patent agent and founder of Menlo Park Patents and WizardIP. He is the named inventor on 103 U.S. patents and many foreign patents. His personal field of work includes medical devices, injectables, dental, chemical, mechanical, electrical, communications, sensors and software. His clients include both large and small entities and individual inventors working in medical, software, mechanical, electrical, chemical, FinTech, distributed ledger technology, cannabis and other technologies. He co-founded Amira Medical, the developer of the first minimally invasive blood glucose monitoring system (sold to Roche Diagnostics) and co-founder of Sterling Medivations, the developer of medication delivery systems sold to SpectRx. Prior to starting Amira medical he worked for Komag the innovator in high-density disk drive technology.

 His entrepreneurial activities have given him an in-depth understanding of the business world and he has helped multiple small companies create valuable digital and technological assets. He has a Master’s degree in Computer Science and a Bachelor’s degree in Civil Engineering. He also holds Professional Engineering licenses in several states.

He also understands the complex requirements of working with the FDA and has authored 29 FDA  510(k)’s for class I/II devices.

Eric MerensteinEric Merenstein is counsel at Lowenstein Sandler LLP, a national law firm with offices in New Jersey, New York, Palo Alto, Utah, and Washington, D.C. He specializes in guiding clients through all phases of patent portfolio development, with a focus on the preparation and prosecution of U.S. and international patent applications within the electrical and computer space. Eric believes in the power of innovation and is passionate about helping innovators protect their intellectual property, from Fortune 500 companies to individuals and small businesses. He has assisted inventors on a pro bono basis through affiliations with organizations such as Volunteer Lawyers for the Arts (VLA) and California Lawyers for the Arts (CLA). 


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