Every flight has a different cancellation policy. This policy not only differs from airline to airline but also differs from domestic to international airlines. In order to cancel a flight, the most common procedure that all airlines follow is that you first call the customer care and then request a flight change. Flight dates/times/routes/names can be changed up to 4 hours before the flight departures. If you are due on any refund, you may not receive it instantly and will have to wait for a few weeks. Always make it a point to check the cancellation policy of the airline before booking your tickets.