Excess baggage fees are charges that airlines impose when a passenger's luggage exceeds the allowed weight or size limits. Each airline has specific rules regarding the maximum weight and dimensions for checked bags, and exceeding these limits can result in additional costs. These fees can vary significantly between airlines and may depend on the route or class of service. Travelers can avoid excess baggage fees by packing efficiently and checking their airline's baggage policy before flying. Some airlines, like Delta or American Airlines, offer options for purchasing additional baggage allowance in advance, which can be more economical than paying fees at the airport.