The present invention provides a system and methods for a radio frequency identification (RFID) system which securely and conveniently integrates important travel-related applications. In accordance with one aspect of the present invention, an RFID system comprises a transponder identification application and various additional applications useful in particular travel contexts; for example, airline, hotel, rental car, and payment-related applications. In accordance with another aspect of the present invention, an RFID system further comprises space and security features within specific applications which provide partnering organizations the ability to construct custom and secure file structures.