No foreigner is allowed to cross the Canadian border if he or she has any convictions on the criminal record. The individual is simply not allowed to pass the Canadian border agents and will have to go back home. Driving under influence is no exception. If you have a single DUI offense on your record, you will be considered inadmissible to Canada. Still, there are ways to get special permission and enter Canada with a DUI. The TRP (Temporary Resident Permit) is a temporary permission for inadmissible people who are flying to Canada but their DUI offense happened less than five years ago.