What is the name of the international treaty that allows a single patent application to be filed in multiple countries?

The Patent Cooperation Treaty is the international treaty that allows one patent application to seek protection in multiple countries.

Usually called the PCT, the treaty was adopted in 1970 and is administered by the World Intellectual Property Organization. An applicant files one international application, receives an international search and written opinion, and can postpone many national or regional filing decisions while evaluating the invention.

The PCT does not create a single worldwide patent. After the international phase, the applicant must enter the national or regional phase in the jurisdictions where protection is wanted. Each relevant patent office then applies its own law and decides whether to grant a patent.

The alternatives in the quiz refer to different intellectual-property systems. The Berne Convention concerns copyright, TRIPS sets broad trade-related IP standards, and the Madrid Protocol provides a route for international trademark registration.