Starting on Wednesday, the Dallas-based carrier will charge customers $35 for their first checked bag and $45 for their second checked bag. The bag fee change will also apply to existing flight itineraries changed on or after May 28, Southwest confirmed to "Good Morning America."

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.

For Southwest Airlines passengers, it's the last day to book a flight with two guaranteed free checked bags no matter which fare they purchase. Starting on Wednesday, the airline will introduce its first-ever checked bag fees,