Top airline executives have been called to testify at a December Senate panel hearing after the Permanent Subcommittee on Investigations released a report on “junk fees.”

According to the report, top airlines including American, Delta, United, Spirit, and Frontier took in $12.4 billion in seating fees between 2018 and 2023. This revenue comes from charging passengers for seats with extra legroom and allowing them to choose their preferred seat.