With many airlines charging fees for extras such as seat selection, checked baggage and more – depending on the fare category you choose – the cost of air travel can end up being steeper than it appears at first glance.

An airline service fee is an administrative charge added to the base fare to cover the costs of processing a transaction or providing a specific non-flight service. These fees can take many forms depending on how you book. If you book through a third-party online travel agency (OTA), the "service fee" typically covers their platform maintenance and customer support. If you book directly through an airline’s call center or at a physical airport ticket counter, they often charge a "Booking Service Fee" (ranging from $25 to $50) for the labor involved in a manual booking that could have been done online. Some airlines also use the term to describe "check-in fees" for passengers who require assistance at the counter rather than using a kiosk or mobile app. Importantly, service fees are usually non-refundable, even if the flight itself is canceled, because the "service" of processing the booking was already performed. These fees are a key part of the "unbundling" strategy used by modern airlines to keep the initial advertised fare as low as possible while generating additional revenue from ancillary services and administrative tasks.