Do you really want to know how much it will cost to change a KLM flight? If a change in plans or a postponement were to occur, KLM Airlines has made it very easy for its travellers to cancel or modify their flights. Any changes made within 24 hours of the initial booking are free of charge and should be achievable via the website or by phone call to the hotline number. The KLM flight change fee is still charged for any changes made to tickets after the allotted 24-hour period has passed. It includes the cost of changing flights, even though that is a cost difference that the traveller is responsible for paying, if any.