You'll want to understand the cancellation policy once you've booked a flight. Is it fully refundable if you cancel it within 24 hours? Is it a policy of the airline to issue refunds within 24 hours of purchase? Is it possible to Cancel Air Canada flight reservation without paying a penalty? All airlines are required by the Department of Transportation to "hold a fare" at the indicated price for 24 hours without payment or to allow reservations to be cancelled without penalty within that time frame. This condition complements Air Canada's 24-hour cancellation policy. This Air Canada flight cancellation policy applies to all domestic and international tickets into and out of the United States and Canada. Special authorization may be obtained during the holiday season or on weekends. a complimentary service for 24 hours period of cancellation For example, if you made a reservation on Friday, you have till Monday to decide on the cancellation portion.