Synchronization is provided between a real-time charging system (22) and an off-line billing system (24) of a communications network. The synchronization is facilitated by the real-time charging system (22) preparing a reporting record which includes information comprising: (1) an accumulated cost parameter associated with the event; (2) the real-time account balance, the real-time account balance reflecting the accumulated cost parameter; and (3) a transaction identifier associated with the event. The reporting record (40) is processed by the off-line billing system (24) so that the balances of a real-time account (34) and a off-line account (54) for a subscriber and be compared and, if necessary, adjusted, or other actions taken.