Passengers don't want to pay for the seat selection due to already booked and selected flight tickets online. Therefore, if you are thinking of seat selection and reservation in advance, you need to hoard information for the Air Canada seat selection fee starting from $10 to $40 CAD per one-way segment. If you are looking for the seat selection and booking within 24 hours of departure time, then you don’t have to pay for seat selection on Air Canada. But in case you cross a certain time frame, then be updated with information about the seat selection fee and including domestic and international flight service with ease.