You cannot use a U.S. patent to prevent someone elsewhere in the world from using your invention. Patents are country-specific and are rights limited to the borders of the issuing country.Find out how to protect intellectual property in other countries. International patent filing under the Patent Cooperation Treaty (PCT) streamlines the global recognition of a patent application. A US patent holder can block importation and sale of an infringing machine, manufacture or composition of matter in the US and can sue for damages. Hire an intellectual property attorney to safeguard your invention under the foreign country patent protection. Under the Paris Convention, inventors who file first in their home country may take up to a year to complete foreign filings. The blocking impact of prior art against future patent applications, however, is worldwide. Even though you are a startup, at least in the beginning, I want to encourage you to preserve the right to file for patent protection in foreign countries. If an invention was made in the United States, then you need to obtain a foreign filing license before you file in another country.