The flights must be booked before March 24, 2025. Frontier Airlines recently launched a Friends Fly Free promotion. Members of the airline’s Discount Den program can get free round trips for companions on bookings made through March 23,

Frontier's summertime deal appears to be in response to Southwest Airlines, which recently announced it will start charging for checked bags.

Frontier Airlines is stepping up its game. The airline announced Tuesday via press release that it will offer customers a free checked bag on select flights this summer.