The Patent Cooperation Treaty (PCT) enables patent applicants to initiate a centralised patent protection for an invention in almost any country in the world (as of October 2016, the number of PCT contracting states is 151) by means of a single international patent application – PCT application, filed with the World Intellectual Property Organization (WIPO).
PCT application makes it possible for its applicant or inventor to file one centralised application (international application) in one patent office (receiving office), i.e. the Bulgarian Patent Office (BPO), in one language, such application having effect in all PCT Member States designated by the applicant in the international application.
The PCT application, however, does not lead to an “international patent”. Depending on the respective country, the applicant has to select national/regional patent offices of the countries or regions, where patent protection is finally desired, within 30 or 31 months after the priority date of the international application. This is the so-called “PCT National Phase”, which in fact is the phase of granting a patent for invention. Each selected national/ regional patent office then independently decides on the patentability of the international patent application in the respective country/region. The entry into a national phase requires payment at the designated and elected offices of the prescribed national (regional) fees, and submission of a translation of the international patent specification into the respective language.
For the purpose of entering a PCT national phase in Bulgaria, the applicant shall file the international application with the Bulgarian Patent Office (BPO) within thirty one months following the priority date of the PCT application.
An international application shall be subject to international search resulting in a report with the relevant state of the art cited therein, as well as a written opinion on the patentability of the invention. The results of the international search make it possible for the applicant to evaluate the chances for the grant of national patents and commercial success of the invention, while the application is still pending in the international phase and the substantial costs are postponed until the national/regional phases.