Flights may be overbooked, and there is a slight chance that a seat will not be available on a flight even if you have a confirmed reservation. In most circumstances, if you are denied boarding involuntarily, you are entitled to compensation. When required by applicable law, the carrier must solicit volunteers before anyone is denied boarding involuntarily. Check with your carrier for the complete rules on payment of denied boarding compensation (DBC) and for information on the carrier’s boarding priorities.