One filing with the force of many: the Patent Cooperation Treaty and its 159 contracting states
Background
The Patent Cooperation Treaty, administered by WIPO, currently has 159 Contracting States. A single international patent application successfully filed under the PCT has the same legal effect as filing separate patent applications in all Contracting States. The treaty establishes a cost-effective means for companies and innovators to seek patent protection for inventions in multiple countries. It also greatly facilitates the processing and examination of international applications by national patent Offices. And it provides the general public with access to the technical disclosures contained in international applications, so that published applications become a searchable record of invention. Applications and related business can be handled through WIPO's ePCT service, and the PCT Applicant's Guide sets out the procedure for filers.
In plain words
PCT Patent Cooperation Treaty — A WIPO treaty under which one international application has effect in all its contracting states.
WIPO World Intellectual Property Organization — The United Nations agency for intellectual property, which administers the PCT.
Contracting State Contracting State — A country bound by a treaty, in whose territory the treaty's provisions apply.