International locations are not included in unaccompanied minor travel. Spirit Airlines requires that children travelling alone as unaccompanied minors must be checked in at the airport. They must also be accompanied through security by a parent or guardian with proper identification. Spirit Airlines charges an additional fee for unaccompanied minors. Spirit Airlines seat selection allows children between the ages of 5 and 14 to travel alone as unaccompanied minors. The itinerary must include only direct or through flights with no change of aircraft required.