Southwest Airlines has put a price tag on checking bags, a coveted free perk that is about to disappear as part of substantial changes the carrier is making to its service.

After today, customers can expect baggage fees when flying with Southwest Airlines as the airline moves to officially eliminate its "bags fly free" policy on May 28. The Dallas airline has finally revealed that the first checked bag will set customers back $35 while the charge to check a second bag will be $45—with some exceptions.

You have just a few more days to buy a ticket on Southwest that includes free checked bags. Here's when the Southwest Airlines baggage policy changes.