A rollover management system (RMS) receives and stores rollover data that includes subscriber identification and a balance of the rollover usage units that may be "rolled-over" to offset overage units used by a subscriber in excess of package plan usage units in a subsequent billing cycle. In response to receiving requests, the RMS presents rollover data elements to the requesting entities. The balance of the rollover usage units may be rolled over and measured in at least one of a plurality of billable units and may be shared by the subscriber's multiple communication services. The rollover usage units expire after a predetermined number of billing cycles where the predetermined number may vary between package plans. The RMS receives post-billing data elements to update the rollover data elements. The RMS is further operative to account for and present for review unbilled communication service usage to subscribers.