If the flight is cancelled or changed, do I need to make up the difference?

1, because of the airline, we can't catch the scheduled flight and have to take other flights. This is your involuntary change. If the price difference is charged, it is of course unreasonable and does not conform to the provisions of the Civil Aviation Administration. All airlines should not charge the difference.

2. If you have to take another flight because you can't catch up with the original flight for your own reasons, and the cabin and discount of the other flight are different from the original flight, it is of course reasonable to make up the difference; Planes are different from cars, trains and ships. The cost of wasting seats caused by your failure to catch a flight is very high. In fact, it is equivalent to you occupying two seats on two flights.

3. If the flight is delayed or cancelled due to weather or other uncontrollable reasons, it is reasonable to charge the difference if you need to take other flights. Although it feels unfair to consumers, in case of force majeure, the insurance company will not compensate, let alone the airline.