An interactive system in which information read from two or more tags (10, 12 or 10, 12') jointly determines a process to be carried out. One of the tags may identify a user by for example his/her store loyalty card number or by a personal identifying tag (or card) in a cordless RF terminal and the other of the tags may be a RF-ID tag storing details of an action to be performed such as the number of credit points to be given to the loyalty card in response to a transaction or provide promotional information to the user. The process may comprise issuing a command to an action server (28, 30) to provide, or instruct the sending of, output information to a user, by for example over a radio link to a cellular telephone apparatus (18, 34, 36) or PDA, or displayed to the user on a video display unit (38).