There are many individuals who are not U.S. citizens that wish to take the Patent Bar. Several categories include:
The patent bar is not administered to aliens who do not reside in the United States. An alien residing in the United States may apply to take the exam. However, to be admitted to take the patent bar, you must establish that your recognition is consistent with the capacity of employment authorized by the United States Citizenship and Immigration Services (USCIS).
If you meet the technical qualifications but are a non-immigrant alien then you may be given limited recognition before the USPTO provided recognition is consistent with the capacity of employment or training authorized by the USCIS.
The General Requirements Bulletin for Admission to the Examination for Registration to Practice in Patent cases Before the United States Patent and Trademark Office has a section that deals with this in detail:
F. ELIGIBILITY OF ALIENS:
No grant of registration except under 37 CFR § 11.6(c). An applicant who is not a United States citizen and does not reside in the U.S. is not eligible for registration except as permitted by 37 CFR § 11.6(c). Presently, the Canadian Intellectual Property Office is the only patent office recognized as allowing substantially reciprocal privileges to those admitted to practice before the USPTO. The registration examination is not administered to aliens who do not reside in the United States.
Limited recognition to practice before the Office in patent matters. Applicants who are lawful permanent residents of the United States may apply for registration. All other applicants who are aliens residing in the United States may apply for limited recognition to practice before the Office in patent matters pursuant to 37 CFR § 11.9(b). To be admitted to take the examination, an applicant must fulfill the requirements as stated above and in 37 CFR § 11.9(b), which includes establishing that such recognition is consistent with the capacity of employment authorized by United States immigration authorities, for example the United States Citizenship and Immigration Services (USCIS), United States Department of State, U.S. Customs and Border Patrol, and the U.S. Department of Labor. The evidence establishing such consistency must demonstrate: (1) the applicant’s authorization to reside in the United States, and (2) the applicant’s authorization to work or be trained in the United States. It must include a copy of both sides of any work or training authorization and copies of all documents submitted to and received from the immigration authorities regarding admission to the United States, and a copy of any documentation submitted to the U.S. Department of Labor. This may include a complete copy of the application for a particular immigration status, the application for a work or training permit, and/or any approved notices related thereto.
Qualifying documentation should specifically show that the immigration authorities have authorized the applicant to be employed or trained in the capacity of representing patent applicants before the USPTO by preparing and prosecuting their patent applications. Any approval that is pending at the time the application is submitted will result in the applicant being denied admission to the examination.
A qualifying alien within the scope of 8 CFR § 274a.12(b) or (c) is not registered upon passing the examination. Therefore, such qualifying aliens will not be patent attorneys or patent agents. Rather, such an applicant will be given limited recognition under 37 CFR § 11.9(b) if recognition is consistent with the capacity of employment or training authorized by immigration authorities. Documentation establishing an applicant’s qualification to receive limited recognition must be submitted with the applicant’s application.