https://groups.google.com/a/ch....romium.org/g/chromiu

American Airlines change flight policy is extremely customer-friendly. Except for basic economy and some tickets that originate outside of North and South America, you won't have to worry about jumping through hoops or losing the entire value of your ticket

https://www.flightzticket.com/....american-airlines-ch

Thai airways Seat upgrade at the Airport: By handing over cash during check-in, you can easily upgrade your class at the airport.


https://www.flightzticket.com/....blog/upgrade-seats-o

Passengers can request a full refund for refundable tickets. For Emirates, all bookings include a cancellation fee. Each person in the group traveling at the same time will be required to pay Emirates Airlines cancellation fees. Although it is very convenient and easy to cancel your flight online after booking, you can also cancel by calling the airline's customer service.

https://www.flightzticket.com/....emirates-airlines-ca

If you cancel your ticket more than 24 hours after booking, a fee will be charged as a service fee.
Eurowings Airlines Cancellation Policy says Flex ticket flyers make it easy to cancel tickets up to 40 minutes before departure.
In some cases, the cancellation fee may equal the ticket price.
There is no undo function in the long position. However, it may be possible for the passenger to reorganize the flight for an additional fee.

https://www.cancelation-policy.....com/eurowings-airli