In March, Southwest Airlines announced that it was ending its popular and longstanding "two bags fly free" policy. Airline Is Rolling Out Dynamic Pricing for Baggage Fees Based on 'Peak' and 'Off-Peak' Flight DatesHow Much Are Checked Bags at Southwest? Starting Wednesday, May 28, one checked bag will cost $35 and a second checked bag will cost $45, according to the Wall Street Journal. Customers who are part of Southwest's top-level loyalty program, Rapid Rewards A-List Preferred, will still get two free checked bags. The next tier down, A-List members, along with Southwest credit card holders, receive one free checked bag.