https://knowt.com/note/c7e7aba7-091b-4b16-b8d5-e1fd6455123a/What-is-the-Cancellation-Policy-for-KLM What is the Cancellation Policy for KLM? If you cancel your booking within 24 hours of purchase(1-844-643-2807), you may be eligible for a full refund, provided the ticket was booked at least 7 days before the flight's scheduled departure.