Thousands of non-immigrant visa applicants who are in the United States choose to apply for their non-immigrant visa at US consulates in Canada or Mexico rather than traveling back to their home countries. This is commonly referred to as Third Country processing. Third Country Nationals (TCNs) seeking non-immigrant visa appointments with a US consulate in Canada need to be aware of recent changes in the process. These procedural changes went into effect September 1, 2010. Previously, appointments were made by using the fee-based Visa Appointment Reservation System (NVARS) and visa application fees were paid at Scotiabank before attending the visa interview. The new appointment system requires applicants to use CSC Visa Information Services to apply for a US visa at a US consulate in Canada.   
As of September 1, 2010, under the new system, persons must first pay the visa application fee (MRV) online in order to be able to make a visa appointment. Because fees must be paid in advance online before being able to check the availability of appointments, this may pose scheduling problems for prospective visa applicants.
Applicants who paid the MRV fee before September 1, 2010, but did not set an appointment have a grace period to use that MRV fee to schedule an appointment through October 1, 2010. After October 1, it will be necessary to pay the fee again in order to make the appointment.
TCNs must be mindful that appointments are not automatic. Two issues which must be dealt with by a TCN seeking to apply for a visa in Canada are 1) getting a visa to enter Canada from the Canadian government. The CSC Visa Information Services website has some helpful entry permit information for TCNs considering applying for a visa in Canada and 2) getting a US consulate to exercise its discretion to process the visa application.
Consular officials have been advised that they can refuse to issue a visa and refer the applicant to his/her home country for processing in cases where the post believes the case fits into a profile indicating fraud or where the applicant has been out of status. Depending on the length of time and the circumstances causing the unlawful presence in the United States, a TCN may need legal assistance to present the case properly and overcome a discretionary refusal on the part of the consular official. Additionally, persons who entered the United States only under the Visa Waiver Pilot Program may also be subject to difficulties in processing at a third country post since their biographical data has previously never been formally submitted to a US consulate abroad.