Abstract: A multi-application data card is capable of substituting for a plurality of existing single-application data cards. The multi-application data card is preferably a smart card recording data relating to a card user and a plurality of card issuers. The following fields are associated with each card issuer: an application code field indicating a type of application provided for the user by the issuer; a PIN field identifying the user; an access code field whereby the card issuer can have access to the fields associated with that issuer but not to fields associated with any other issuer; an account number field; an expiration date field; and a miscellaneous data field provided for the issuer to record additional data to facilitate its operations. The fields associated with each issuer are separate from the fields associated with every other issuer.

Abstract: A multi-application data card is capable of substituting for a plurality of existing single-application data cards. The multi-application data card can be a smart card comprising a memory formed with at least three memory banks or storage areas for storing and updating data relating respectively to at least one authorized holder of the card and at least two authorized applications of the card. Alternatively, the data card can be a conventional card having a magnetic stripe, and the memory functions can be performed at a location remote from the card reader and connected thereto by a data link. In addition, the data card can comprise both a magnetic stripe and solid-state circuitry so that it can be read by a card reader compatible with a magnetic-stripe card or by a card reader compatible with a smart card. In accordance with the invention, a card holder needs to carry just one card for all card uses, both financial and non-financial.