Abstract: The present invention provides a generic extension module, such as a billing extension module, that can be used to extend a carrier's application's support for real-time billing events. Billing events are triggered around billable operations in the carrier's application, such as the operation to accept a message that was submitted to a server or the operation to deliver a message. The start of an event is triggered before the operation is performed and the end of the event is triggered after the operation is performed. An application can trigger the same event for different operations. Each billing event has associated with it a billing record that has data about the operation and that can be used to charge for the operation that triggered the event. Events can also be linked together if charges are based on the execution of related operations.