The carrier announced Tuesday that it will begin charging certain passengers to check their luggage on flights, a significant shift at the company long prized by consumers for its perks.

Southwest Airlines will begin charging customers a fee to check bags. It's a significant change for the budget carrier, which built years of advertising campaigns around its policy of letting passengers check up to two bags for free.

"Bags fly free" was a staple slogan for the Dallas-based airline, which trademarked the phrase in 2012. Members of Southwest's top-tier A-List Preferred rewards status and Business Select fliers will still be able to check two bags for free, and A-List members can check one.