KLM Flight Cancellation Policy gives passengers the option to cancel their flight within 24 hours of booking and obtain a full refund if the flight leaves in more than 7 days. You can cancel your flight online using the KLM website or offline by contacting customer service. Remember to read the terms and conditions so that you can be eligible for a full refund. https://medium.com/@gimmibala/can-i-cancel-a-flight-within-24-hours-at-klm-9cbaca5436a6