Terminal # 1 called FBO is exclusive for charter flights and private flights arrivals, if you are travelling to Cancun in a charter flight, that is the terminal where you will arrive and depart. There are two terminal buildings in the Cancun airport.
Terminal # 2 receive national commercial flights: Aeromexico, Air Canada, Air Transat, Air Tran Airways, Aviacsa, Belair Airlines Click de Mexicana, Champion Air, Condor, Copa Airlines, Cubana de Aviación, First Choice Airways, Interjet, JetBlue Airways, Jetair, Lan Chile, Magnicharters, Martin Air, Mexicana, SkyService Airlines, SunWing Airlines, Varig, Viva Aerobus, Volaris.
Terminal #3 All other International Flights use Terminal 3. Airlines: Air Europa, Alaska Airlines, American Airlinee, ATA Airlines, Continental Airlines, Delta Airlines, Frontier Airlines, Iberworld, LTU, My Travel, Northwest Airlines, Sun Country Airlines, Thomas Cook, Thomson Fly, United Airlines, US Airways, USA 3000
Transfer Between Terminals. A FREE airport shuttle service runs between the terminals every 20 minutes.