If you need to rebook a TUI flight (TUI Flug umbuchen), the process is generally straightforward. TUI allows passengers to change their booking through their website, app, or customer service. Depending on the fare type and conditions, you might be subject to rebooking fees and fare differences. Flexible tickets usually offer easier changes, while more restrictive fares may incur costs. It's important to check the terms and conditions of your ticket. You will need your booking reference, last name, and sometimes payment details for any fee adjustments