On June 19, 1970, the Patent Cooperation Treaty (PCT) was signed by 18 different countries in Washington D.C. at the end of an international conference. In particular, the 18 countries signed the PCT in an effort to better harmonize the international patent application process.

The PCT is an international patent law treaty designed to unify the procedure for filing patent applications to protect inventors in “Contracting States” (i.e. members of the PCT). While no “world” or “international” patents exist, the PCT gives inventors the opportunity to file for protection for the same invention, at the same time, in more than one country.

The PCT has two main phases. The first phase is the international phase in which applicant files a single patent application, in one language, in any of the Contracting States of the PCT. In other words, only one application form, one language, and one set of fees needs to be filed to preserve the same legal effect as filing in every Contracting State.

The second phase encompasses the national and regional phase where the applicant must actually go through the necessary steps to gain patent protection in each separate Contracting State (i.e. each country where the applicant wants a patent). This is because the PCT application is not a world or international patent. Rather, the PCT acts to lock in the same filing date for every country and grants the applicant the possibility to obtain a patent in every Contracting State.

The PCT process saves time, money, and gives a patent applicant much information on the likelihood of receiving a patent in the different countries. In particular, the International Searching Authority (ISA) conducts a search on the patentability of the patent and provides a written opinion on the patent’s likelihood of being patented to the applicant. Further, the International Preliminary Examining Authority (IPEA) may conduct a preliminary examination of the patent to give the applicant even more useful information. So, by the time the applicant needs to consider national applications in Phase 2, the applicant can make a more well-informed decision.

The PCT has been amended multiple times but continues to act as the foundation for how international patent applications are made.

Today, nearly all the world’s industrialized countries are Contracting States to the PCT. At last check, over 140 countries are Contracting States.