Canada has introduced a new entry requirement, known as Electronic Travel Authorization (eTA), for visa-exempt foreign nationals travelling to Canada by air.
Citizens of certain countries and territories need a visa to visit or transit Canada. Others need an eTA.
Applying for an eTA is a simple online process that takes just a few minutes. To apply you must have a valid passport, credit card, and email address.
You must also make sure that you:
More information: http://www.cic.gc.ca/english/visit/eta.asp
Apply for an eTA