The Patent Cooperation Treaty (PCT) is an international treaty that allows Applicant to seek patent protection in mulitple signatory countries by filing a single patent application. The PCT has been signed in 1970, and since then has been growing in importance and size and currently has 146 contracting nations, including the United States. Signatories to the PCT agree to follow the procedures established by the treaty, but reserve the power to grant or deny patent protection based on their own national substantive patent laws.
One of the purposes for which the PCT was enacted is simplifying and harmonizing the filing procedures and reducing the associated costs when patent protection for an invention is being sought in multiple countries. The PCT attempts to accomplish this goal by establishing a concrete set of formalities and requirements. A compliant PCT patent application must contain the following elements: a request, a description, one or more claims, one or more drawings (where required), and an abstract. In addition, Applicant must be a resident or a national of a country signatory to the PCT. The filing of a patent application under the PCT automatically establishes a priority date in all participating countries, and a PCT application may further claim priority to one or more earlier filed national patent applications. In practice, filing a PCT application is fairly straightforward: the application must meet the formalities listed above, must be designated as a PCT application, and must be filed at a receiving office by an applicant who is either a resident or a national of a PCT contracting state.