Reservations may be Cancelled without Penalty for 24 hours After Purchase. You can also cancel your buy of tickets up to 24 hours after buy and Air Canada will provide you with a complete refund without penalty. This policy applies to refundable as well as non-refundable fares. There are many instances when you might not want to take your flight at your destination or would like to cancel your flight. Understanding such situations, Air Canada lets you to cancel your flight. However, there are a few guidelines concerning the cancellation. As in keeping with the Air Canada Cancellation Policy