An Electronic Travel Authorization (eTA) is an entry requirement for visa-exempt foreign nationals travelling to Canada by air. An eTA is electronically linked to a traveller's passport. It is valid for up to five years or until the passport expires, whichever comes first.
Before you arrive in Canada, you may be asked to complete a Customs Declaration Card. Complete this card before meeting with customs and immigration officials, even if you aren't a Canadian citizen. If you're traveling by air, it's a good idea to complete the card before you leave the airplane.
Who already have a visa in their passport. Travelers may wish to avoid buying plane tickets until they have obtained an ESTA (or a valid visa, in case the ESTA is not approved). ESTA applications may be submitted at any time prior to travel. The processing of an ESTA can take up to 72 hours.