As part of the method for operating pay stations of an ID-based access control system for a post-payment scenario comprising a central server (1) and at least one access control device (5), each access control device (5) of the access control system is assigned to a zone and each pay station (4, 4′, 4″) is assigned to a zone. Each zone comprises a unique zone-ID and, at the start of the execution of the method for each zone a presence record created in the central server (1) is forwarded via one or more proxy-servers (2,3) to the pay stations (4, 4′, 4″) of each zone and stored in the pay stations (4, 4′, 4″). Subsequently, at pre-set, definable time intervals or when the Delta changes recorded in the central server (1)—namely the IDs of the customer media no longer present in the zone and the IDs of customer media newly added—a pre-set threshold in a zone for the customer media newly added in this zone and/or for the customer media no longer present in the zone is exceeded, a file containing the Delta changes for updating the presence record stored in the pay stations (4, 4′, 4″) is transmitted via one or more proxy-servers (2, 3) to the pay stations (4, 4′, 4″).