age of child for unaccompanied
1 Children ages five through 11 traveling without an accompanying Passenger age 12 or older must travel as an Unaccompanied Minor (UM) on Southwest Airlines. 2  For travel booked on or after April 23, 2010, Southwest Airlines will charge $50 each way ($100 roundtrip) in addition to the air fare per child for UMs to travel.eâre a click away. 1  Children ages five through 11 traveling without an accompanying Passenger age 12 or older must travel as an Unaccompanied Minor (UM) on Southwest Airlines.