For decades, it was free on major airlines to check at least one bag (some discount airlines got a head start on charging). But in 2008, amid rising fuel prices and economic turmoil, that started to charge. Airlines such as American and United began tacking on a $15 charge to get your bag checked to your destination.

The era of universal checked bag fees began in May 2008, when American Airlines became the first major U.S. legacy carrier to announce a $15 fee for the first checked bag. This was a direct response to the global financial crisis and skyrocketing jet fuel prices, which had reached record highs of over $140 per barrel. Following American's lead, most other major airlines—including United, Delta, and US Airways—implemented similar fees within months to create a new "ancillary revenue" stream. Prior to 2008, checking one or two bags was almost always included in the price of a domestic economy ticket. This shift essentially "unbundled" the flight ticket from the luggage service, a model that had been pioneered by ultra-low-cost carriers like Ryanair in Europe and Spirit in the U.S. In 2026, these fees have nearly tripled, with $35 to $45 being the standard for a first bag, leaving Southwest Airlines as the only major U.S. carrier that still offers two free checked bags as a core part of its brand promise.