Study and work permit holders from visa-exempt countries who received their permit on or before July 31, 2015 are expected to have an eTA as of March 15, 2016 to fly or transit to Canada. Note: until September 29, 2016, study and work permit holders who do not have an eTA can board their flight, as long as they have appropriate travel documents, such as a valid passport.
Applicants who are issued an initial study or work permit on or after August 1, 2015 will automatically be issued an eTA along with their permit. For work permit or study permit renewal applications, the eTA will not be automatically renewed. If you wish to exit and re-enter Canada by air, you will need to ensure that your eTA is still valid by consulting the Check Status Tool. If your eTA has expired, you will need to apply for a new one as soon as you can and before the eTA leniency period ends on September 29, 2016.