Apparatus for access control and processing

A computer-based ticket system enables users to electronically transfer tickets to other users, and to obtain tickets from other users. A first software module executing in a server is configured to cancel a first ticket for a first seat at first event associated with a first user, and issue a second ticket for the first seat to a second user at least partly in response to an instruction from the first user received from a first user terminal and an instruction from the second user received from a second user terminal.