A universal electronic transaction card ("UET card") is capable of serving as a number of different credit cards, bank cards, identification cards, employee cards, medical and health care management cards and the like. The UET card includes storage elements, an input interface, a processor, a display, and a communications interface. In a preferred embodiment, the UET card stores transactional information to eliminate paper receipts and includes security features to prevent unauthorized use. The UET card may also be used to replace conventional currency and traveler's checks, and may be configured to store and display promotional information, such as advertising and incentives.
The invention also includes systems for using UET cards, for example, health care management systems, communication interface units, and methods for using the same, including methods of issuing an account authorization to a UET card, a method of transferring transactional and account information between a UET card and a personal computer or a mainframe computer, a method of using the UET card as a remote terminal for a mainframe computer, and a method of conducting an electronic transaction.