En español | Q: Dear Peter, If we should cancel a trip after booking the airfares, or we need to change the date, what is the penalty? Also, what does flight insurance cover?
–Martin Lassa, Miami, Fla.

A: I think we all wish that returning or changing airline tickets were as simple as leaving the tags on a clothing purchase and keeping the receipt. However, Martin, as you already know, it's not always that easy.

The first question is whether you purchased a nonrefundable or refundable ticket. The latter is a pricier option, but offers flexibility in terms of changing the date of your flight without penalty.

See Also: 4 Tips: Landing bargain airfares.

However, if you purchased a nonrefundable flight, you can cancel your existing reservation and hold on to the credit for up to a year from the purchase date. But expect to face hefty fees for that privilege. 

For domestic flights the change fee on average is about $150, and for international flights it is usually about $250. The prices vary depending on the airline, and the price fluctuates depending on the type of fare bought and the location of the flight. And to add insult to injury, the airlines may charge you the difference if the fare increases.

I should note that Southwest Airlines doesn't charge a change fee, but still charges a fare difference.