Imagine being stuck in another country because you misplaced or do not have the required documentation to return. This is a definite possibility if you do not take the time to attain the appropriate documentation. With the exception of citizens of the United States, St. Pierre or Miquelon, all others require either a valid Temporary Resident Visa (TRV) or Electronic Travel Authorization (eTA) to re-enter Canada. Not sure what document you require? Go here.