TUI fly's cancellation policy indicates that flight reservations are generally non-refundable, with cancellations incurring a 100% charge. However, passengers can request a refund of passenger-related taxes and fees for unused flight segments, subject to a processing fee of €35 per request. Cancellations must be submitted in writing before the flight date and are processed on workdays during business hours (Monday through Saturday, 9:00 am to 5:00 pm). It's advisable to consider purchasing cancellation insurance to mitigate potential financial losses due to unforeseen cancellations.