Low-cost carrier Frontier Airlines is the most likely to bump passengers, far surpassing other major airlines in the United States. 

Frontier involuntarily bumped 3.21 people per 10,000 passengers from the beginning of 2023 to 2024, according to a study from Upgraded Points that was shared with Travel + Leisure. That was 400 percent more than any other U.S. airline.

American Airlines involuntarily bumped the second-most passengers in the country with a rate of 0.60 per 10,000 travelers, followed by Spirit Airlines with a rate of 0.43 per 10,000 travelers.

"Few travel experiences are more frustrating than being bumped from a flight after purchasing a ticket. Yet it happens frequently since airlines routinely sell more tickets than available seats in anticipation of no-shows," Keri Stooksbury, the editor-in-chief at Upgraded Points, said in a statement shared with T+L. "We studied this industry practice to give travelers a heads-up on which carriers are most likely to have this issue."

On the other end of the spectrum was Delta Air Lines and Allegiant Air, which each boasted zero involuntary denied boardings. However, Delta did have the highest number of voluntary bumps with a rate of 7.49 per 10,000 passengers.

Airlines often offer compensation for volunteers willing to be bumped when the airline overbooks flights. That compensation can include anything from cash to an upgraded seat on a later flight or lounge access. 

However, the Upgraded Points study found the amount of compensation travelers are willing to accept to miss their scheduled flights varies by state. In Arkansas, for example, travelers will agree to be bumped for an average minimum of $382, according to the study. But in California, passengers demand a higher rate with an average minimum of $832.

The layover wait time and time of year (like if it’s the holidays) also play into whether or not travelers are willing to give up their seats.