New visa requirements for travelling through Canada
How to find out if you need an Electronic Travel Authorization (eTA) or a visitor visa
As of March 15, 2016, visa-exempt foreign nationals are expected to have an Electronic Travel Authorization (eTA) to fly to or transit through Canada. Exceptions include U.S. citizens, and travellers with a valid Canadian visa. Canadian citizens, including dual citizens, and Canadian permanent residents are not eligible to apply for an eTA. However, from March 15, 2016 until fall 2016, travellers who do not have an eTA can board their flight, as long as they have appropriate travel documents, such as a valid passport. During this time, border services officers can let travellers arriving without an eTA into the country, as long as they meet the other requirements to enter Canada. Follow this link to VisitCanada.gc to find out if you need a visa and for answers to your questions about the leniency period.