Systems and methods for performing online charging for proximity services. One embodiment is a proximity service element that controls proximity services for a mobile network. The proximity service element receives a service request from User Equipment (UE) for a proximity service, and collects online charging information related to the proximity service. The proximity service element formats the online charging information into an online charging request, and transmits the online charging request to an online charging system. The proximity service element receives an online charging response from the online charging system that includes a credit authorization result for the proximity service, and transmits a service response to the UE indicating the credit authorization result for the proximity service.