Systems and methods for synchronizing online and offline charging data are disclosed. In some implementations, a charging trigger machine (CTM) determines that charging data for a mobile user account at an online charging system (OCS) and charging data for the mobile user account at an offline charging system (OFCS) are to be synchronized. The CTM sends a credit control request (CCR) to the OCS. The CTM sends an account charging request (ACR) to the OFCS simultaneously with sending the CCR to the OCS and in response to determining that the charging data at the OCS and the charging data at the OFCS are to be synchronized. The ACR includes an instruction for a service data container (SDC) level trigger to be added to an output charging data record (CDR) created at the OFCS and associated with the mobile user account.