If you're flying during the upcoming holiday, you need to know what your rights are if you get bumped from a flight.

Here are the most important things you need to know about voluntary and involuntary bumps from flights according to the U.S. Department of Transportation.

Voluntary bumps

At the check-in or boarding area, airline employees will look for volunteers when it appears that the flight has been oversold. If you're not in a rush to arrive at your next destination, you can give your reservation back to the airline in exchange for compensation and a later flight. But before you do this, you may want to get answers to these important questions:

When is the next flight on which the airline can confirm your seat? The alternate flight may be just as acceptable to you. On the other hand, if the airline offers to put you on standby on another flight that's full, you could be stranded.

Will the airline provide other amenities such as free meals, a hotel room, transfers between the hotel and the airport, and a phone card? If not, you might have to spend the money it offers you on food or lodging while you wait for the next flight.

DOT has not mandated the form or amount of compensation that airlines offer to volunteers. DOT does, however, require airlines to advise any volunteer whether he or she might be involuntarily bumped and, if that were to occur, the amount of compensation that would be due. Carriers can negotiate with their passengers for mutually acceptable compensation. Airlines generally offer a free trip or other transportation benefits to prospective volunteers. The airlines give employees guidelines for bargaining with passengers, and they may select those volunteers willing to sell back their reservations for the lowest price. If the airline offers you a free ticket or a transportation voucher in a certain dollar amount, ask about restrictions. How long is the ticket or voucher good for? Is it "blacked out" during holiday periods when you might want to use it? Can it be used for international flights?

Involuntary bumps

DOT requires each airline to give all passengers who are bumped involuntarily a written statement describing their rights and explaining how the carrier decides who gets on an oversold flight and who doesn't. Those travelers who don't get to fly are frequently entitled to denied boarding compensation in the form of a check or cash. The amount depends on the price of their ticket and the length of the delay:

If you are bumped involuntarily and the airline arranges substitute transportation that is scheduled to get you to your final destination (including later connections) within one hour of your original scheduled arrival time, there is no compensation.

If the airline arranges substitute transportation that is scheduled to arrive at your destination between one and two hours after your original arrival time (between one and four hours on international flights), the airline must pay you an amount equal to 200% of your one-way fare to your final destination that day, with a $675 maximum.

If the substitute transportation is scheduled to get you to your destination more than two hours later (four hours internationally), or if the airline does not make any substitute travel arrangements for you, the compensation doubles (400% of your one-way fare, $1350 maximum).

If your ticket does not show a fare (for example, a frequent-flyer award ticket or a ticket issued by a consolidator), your denied boarding compensation is based on the lowest cash, check or credit card payment charged for a ticket in the same class of service (e.g., coach, first class) on that flight.

You always get to keep your original ticket and use it on another flight. If you choose to make your own arrangements, you can request an "involuntary refund" for the ticket for the flight you were bumped from. The denied boarding compensation is essentially a payment for your inconvenience.

If you paid for optional services on your original flight (e.g., seat selection, checked baggage) and you did not receive those services on your substitute flight or were required to pay a second time, the airline that bumped you must refund those payments to you.

Click here to read the exceptions to these rules and other information about overbooking.