DENVER (AP) — Frontier Airlines, which has struggled more than other U.S. carriers to recover from the pandemic, says it is eliminating change fees on some tickets and creating four fare classes to boost its appeal to more travelers.

The Denver-based airline said the changes taking effect Friday would make buying a ticket less complicated.

Frontier, like rivals Spirit Airlines and Allegiant Air, advertises low fares but tacks on more fees than the larger carriers. Consumers pick from a menu of extras that increase the final price they pay — often by a significant amount.

The budget carriers have struggled, however, as big airlines created their own no-frills tickets to lure away the most cost-conscious travelers.

Frontier is switching to four fare classes, which it calls basic, economy, premium and business. Those in “basic” will still have to pay extra for things like bringing a carry-on bag, selecting a particular seat and changing or canceling a reservation.