An international patent filing treaty administered by the World Intellectual Property Organization (WIPO). The Patent Cooperation Treaty (PCT) allows an applicant to seek patent protection in each of the PCT contracting states by filing a single initial PCT international patent application instead of separate applications in each desired country. Each designated contracting state then grants its own national or regional patent if the PCT application meets the conditions for patentability in that country or region. The PCT does not provide for a single international patent.

Any country that is a party to the Paris Convention for the Protection of Industrial Property (Paris Convention) may become a PCT contracting state, and there are more than 178 contracting states.

The procedure for filing generally includes the following steps:

If the applicant then proceeds with the national application process, separate patent applications must be filed in each of the countries or regions where the applicant desires a patent.

Filing a PCT patent application also allows an applicant to delay filing most national patent applications for at least 30 months from the application's priority date.

For more information on filing PCT applications in the US, see Practice Note, PCT Patent Applications: Filing in the US Receiving Office

Additional information on the PCT is available on the WIPO website.