Canada to require Electronic Travel Authorization 'eTA') for entry via a flight; applies only to visa-exempt foreign nationals (US citizens are visa-exempt - they don't need an eTA)
Electronic Travel Authorization – Flights to Canada:
The Government of Canada has recently introduced a new entry requirement, known as an Electronic Travel Authorization (eTA), that applies to visa-exempt foreign nationals* traveling to or transiting Canada by air. Effective March 15, 2016, visa-exempt foreign nationals must obtain an eTA before they can board a flight to Canada. To complete an application for an eTA, the traveler will need their passport, a credit card and an email address. An eTA costs $7 CAD and is valid for up to five years.
Among those exempted from this new requirement are U.S. citizens and travelers with a valid visa. As well, entry requirements for travelers arriving by land or sea have not changed.
To see if the citizens of a particular country need an eTA or for them to apply for one, visit the Government of Canada's Electronic Travel Authorization website:
* A visa-exempt foreign national is a person who is not a citizen of Canada and is not required to obtain a visa for the purpose of travel based on their country of nationality.