Can a citizen of another country apply for a patent or trademark in the United States?
Yes. Anyone can apply for a patent or trademark in the United States. The patent application should be filed by the inventor. If there is more than one inventor, all inventors should be involved. Each inventor must provide his/her address and nationality. Be careful: Many countries consider filing for a patent in another country to be a criminal offense when done without first obtaining permission from the national patent office.
