What allows a company to file a single patent application for multiple countries?

The ability for a company to file a single patent application that is applicable in multiple countries is facilitated by the Patent Cooperation Treaty (PCT). The PCT provides a unified procedure for filing patent applications, which allows inventors to seek patent protection internationally by filing one application with a single authority.

This system simplifies the process of securing patents in multiple jurisdictions, as it allows applicants to avoid the complexity and costs associated with filing separate applications in each country where they seek protection. The PCT application is then examined by the participating national patent offices in due course, which can streamline the patent grant process across different nations.

The other entities mentioned do not serve this specific purpose. The World Trade Organization (WTO) primarily focuses on global trade rules and agreements but does not handle patent applications directly. The International Copyright Agreement pertains to the protection of creative works and does not concern patents. The World Intellectual Property Organization (WIPO) oversees international intellectual property laws and treaties, including the PCT, but it does not itself provide a platform for filing patents; rather, it administrates treaties like the PCT.