Carnival offers interline discounts on select sailings to Vacations To Go customers who are currently employed full-time with a domestic or international commercial passenger airline, other cruise lines, Airline Pilots' Association (ALPA), Federal Aviation Administration (FAA), International Air Transport Association (IATA), National Air Traffic Controllers Association (NATCA), Amtrak, Worldspan, Sabre, Galileo, Amadeus, FedEx and UPS. These guests may book two staterooms at the interline discount for themselves and their immediate family members, including interline eligible guest's spouse, parents and dependent children age 21 or younger, as long as one interline eligible guest is traveling on the same ship and sailing date. The Spouse, Parent, or dependent child (age 21 or younger) of an interline eligible guest may book one stateroom if the interline eligible guest is not traveling. Retired airline employees are also eligible to book one stateroom provided the airline is still in operation. Qualifying interline personnel must submit a photocopy of their company photo ID via fax to Carnival and Vacations To Go at the time of booking. Carnival will charge guests the standard market rate if they do not receive proper documentation within 72 hours of booking (24 hours for reservations inside of 2 weeks prior to sailing).