postheadericon What is a PCT?

Well, it is not a patent – there is no such thing as a “granted international patent.”  In reality, “PCT” has two meanings. To begin with, it is the official acronym for Patent Cooperation Treaty, which is a binding agreement between numerous countries to cooperate in the action of protecting inventions. However, PCT is also patentspeak for the application that gets filed under the Patent Cooperation Treaty as well as its processes.

Say what? I can imagine the confusion generated by that sentence from here.  🙂

PCTs (the applications themselves, not the international alliance treaty they’re named after) are both fairly simple yet quite complex.  The top-level process itself is not that difficult, but the management of each step can be rather complicated. As a matter of fact, there are several conferences each year dedicated to the art and science of filing & prosecuting PCT applications. I could easily spend days explaining it all. But… every journey needs a point of origin, so we’ll start from the top. I hope that this overview helps clarify some of the confusion surrounding the prosecution of these applications.  Should you wish further information, or if you have any questions, please feel free to raise your hand and post your questions in the comments… class is in session!


As we are talking shop here, I’ll focus mostly on the PCT as it applies to the application itself and provide a general overview of how it is processed. A PCT application is basically a virtual “place holding” application for an invention, and is applicable for a specifically limited amount of time in specific countries or groups of countries that are members of the Patent Cooperation Treaty as of the filing date of the application.  After a certain amount of time, that PCT application effectively “dies” and is transformed into applications in specific countries where the individual filing fees are paid… i.e. – it enters the national phase.

When the national phase is entered (at the national stage of the application), the PCT application becomes the actual national application and the PCT filing date is the actual, official national filing date. It keeps the priority and includes all amendments and changes that were made to the PCT application at the time the national stage was entered.  That is why most countries do not require that a copy of the PCT application be filed – they should have already received it from the International Bureau.

In order to understand what the PCT is and what a PCT application is, we need to first define some words.  The patent world has its own vocabulary and can surprise you with a word that doesn’t mean what you think it should.  Here are some definitions to keep in mind when you read this paper:

Patent = A government license that gives the holder exclusive rights to a process, design, or new invention for a designated period of time (i.e., the right to exclude others from making, using, offering for sale, or selling the invention in the jurisdiction that is protected by that government’s license for a specifically designed number of years).

Cooperation = an act or instance of working or acting together for a common purpose or benefit; joint action

Treaty = a formal agreement between two or more states in reference to peace, alliance, commerce, or other international relations; the formal document embodying such an international agreement

State = a politically unified people occupying a definite territory; nation

PCT = Patent Cooperation Treaty = an agreement between a number of countries to cooperate in the action of protecting inventions for a certain amount of time. 

Article 1(1) of the Patent Cooperation Treaty: “The States party to this Treaty … constitute a Union for cooperation in the filing, searching, and examination, of applications for the protection of inventions…”

Organization (WIPO) (PCT Article 2(xvii)): the World Intellectual Property Organization (more on this later)

International Bureau (IB) (PCT Article 2(xix)): International Bureau of the Organization and, as long as it subsists, the United International Bureaux for the Protection of Intellectual Property (BIRPI)

Receiving Office (RO) (PCT Article 2(xv)): The international application shall be filed with the prescribed receiving Office, which will check and process it as provided in this Treaty and the Regulations.  (i.e., a national patent office of or acting for a Contracting State [or region] which is a member of the PCT)

National Office (PCT Article 2(xii)):  …the government authority of a Contracting State entrusted with the granting of patents; references to a “national Office” shall be construed as referring also to any intergovernmental authority which several States have entrusted with the task of granting regional patents, provided that at least one of those States is a Contracting State, and provided that the said States have authorized that authority to assume the obligations and exercise the powers which this Treaty and the Regulations provide for in respect of national Offices

PCT Application: an application for the protection of an invention filed under rules and regulations of the Patent Cooperation Treaty, including applications for patents for inventions, inventors’ certificates, utility certificates, utility models, patents or certificates of addition, inventors’ certificates of addition, and utility certificates of addition.


The Treaty entered into force on January 24, 1978 with 18 contracting states. It currently has 142 member states.  Since this is an international Treaty, it needs to be administered by an impartial entity. That entity is the World Intellectual Property Organization (WIPO).  WIPO is a specialized agency of the United Nations, which is dedicated to developing a balanced and accessible international intellectual property system (see for more information about WIPO).  There is a special section of WIPO that is responsible for enforcing the rules of the Treaty and managing the prosecution and administrative process of the Treaty, which is the International Bureau (IB). 


Why file a PCT application?  The main advantage of a PCT application is that an applicant can delay the filing of national or regional patent applications (which includes paying the fees for required translations, attorney costs and filing fees) for up to (generally) 30 months from the initial filing of an application.  Foreign applications can be very expensive (from $1,500 up to $10,000 or more for each application).

The first decision that needs to be made is whether or not the owner of an application believes that there is a market for the invention outside of the US (or other country in which the initial filing was made).  If so, then the owner needs to identify these countries of interest.  In many cases, the owner cannot identify the countries at the required time, or they wish to delay the associated costs as long as possible.  That would be the time when a PCT application can be useful (there are also other strategic reasons for filing a PCT application – please contact your attorney for advice on foreign filing, as I do not provide legal advice).

There are two parts to the Treaty that need to be considered – Chapters I and II.  The Treaty itself includes eight (8) chapters, but only Chapters I and II deal with the filing and prosecution of applications for invention – the rest of the chapters address the administrative portions of the Treaty.

Every PCT application is filed under Chapter I of the Treaty.  A PCT application consists of (at least) a Request, a Fee Sheet and the patent application (additional requirements can also apply).  The application is then filed in a competent Receiving Office[1].  Once a PCT application is filed, the applicant gains additional time in which to file foreign applications.

A PCT application can claim priority to an application that was filed no longer than one year prior to the filing date of the corresponding PCT application.   All dates are calculated from either the filing date of the earliest claimed priority application or, if there was no priority application, from the filing date of the PCT application.

The “additional time” in which to file national applications is 30 months[2] (except for Luxembourg, Uganda and the United Republic of Tanzania, which is 20 months unless the PCT application enters Chapter II) from the earlier of the filing date of the PCT application or the filing date of the oldest patent application (if any) to which each PCT application claims priority[3].   

CHAPTER I – International Application and International  Search

Once a PCT application has been filed, it will continue on for a while, then it will be searched, a written opinion will be established and then the application and search report will be published.   Once the application has been published, the applicant has the option to amend the claims of the application – such amendment must be filed within a limited amount of time.  Once the amended claims have been received by the IB, the new claims will be published.  Eventually, the IB will re-issue the written opinion as a Chapter I – International Preliminary Report on Patentability (scheduled for issue at 28 months). 

There are specific times when portions of the application can be amended or other documents filed, but once the application is complete no further action really needs to be completed by the applicant or attorney other than responding to any Invitations issued by the IB.  Additional actions can be done, but once the application is complete and all formalities done, the only time action need be taken is if something goes wrong.  It is very important, however, that the application be monitored by someone who knows what should happen and what documents should be issued and the due dates for each of the documents.  For instance, if the search report is not timely issued, someone should follow-up with the searching authority to find out why.  Additionally, there are specific documents & receipts that are issued by the IB that also should be monitored to ensure that they are correctly and timely issued.

CHAPTER II – International Preliminary Examination Report  

“Chapter II Demand – Request for Preliminary Examination” is the official name of the document that must be filed in order to enter Chapter II, but it is commonly just referred to as the “Demand.”  There could be many reasons to file a Demand (again, consult with your attorney), but the main reason is that you want to respond to the examiner’s written opinion and/or you want to amend the application.  Once a Demand is filed (and any amendment), there is one opportunity to discuss (either written or verbally) the application with the examiner.  Certain specific steps need be taken, though, to ensure that the examiner knows that you wish to speak with them during examination.  Once this process is complete, the examiner will issue the Chapter II – International Preliminary Report on Patentability, which should also be issued by month 28.

This is the time when the applicant needs to make a final determination as to which countries the application should be filed.   Instructions should be sent to your associate at least one month prior to the final due date.  They can be sent later, but there is also the risk that the associate (foreign law firm) will end up charging expedited fees for the filing and/or translation.  Translations can be very expensive – I’ve had a situation where a translation into Russian cost over $8,000.  If that had been expedited, it could have cost $16,000!  So whenever possible, send instructions to your associate as soon as possible.

When a PCT application enters the national stage and national phase applications are filed, the national application receives an “official filing date” as of the PCT application and retains the priority date.  Priority dates can be very important when the application is being examined and prior art is revealed. 

Below is a basic timeline for PCT applications:


In summary, a PCT application is a virtual application in every country that is a member of the Patent Cooperation Treaty.  It essentially reserves a priority date for the invention to give the owner extra time to determine where the invention should be protected. In most cases, that means that the owner can do additional marketing and/or research to find out where they would have the most success in selling the product.  Inventions can take several years before they are fully marketable – this extra time can be extremely valuable to the owner of this type of product.

Remember that the invention that was disclosed in the PCT application will normally become public knowledge as of the publication date of the PCT application wherever the national phase applications are NOT filed.  This is something all too many people forget, or that the applicant of a PCT application may not fully realize.

I hope that this provides you with at least some clarification of the value of PCT applications and the basic process.  Please remember that this is only a brief explanation of the PCT process – there are additional documents, requirements and steps that can or should be taken during the PCT application.

Please feel free to post your questions below in the comments section.

[1] A competent Receiving Office is the national patent office of or acting for the Contracting State of which one or more applicant is a resident or national when the application is in a language that is accepted by that national patent office.  The International Bureau is a competent Receiving Office for any application in which at least one applicant is a resident or national of a Contracting State.  See PCT Rule 19 for further information on what constitutes a competent RO. 

[2] National Phase applications are due at 30 months in most countries – some countries have a due date of 31 months (e.g., Europe, South Korea and several others), filing of national phase applications in China can (currently) be extended to 32 months and in Canada to 40 months.  Please contact your attorney for the current actual due dates.

[3] A PCT application may claim the priority of one or more earlier applications filed either in or for any country party to the Paris Convention for the Protection of Industrial Property or in or for any Member of the World Trade Organization that is not party to that Convention.  Any priority claim shall be made in the request, it shall consist of a statement to the effect that the priority of an earlier application is claimed and …  (Rule 4.10 PCT)  NOTE:  this is NOT a full explanation of priority or when and what can be claimed as priority.  Priority is also further defined in Article 4 of the Paris Convention.

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