This invention relates to the field of communication technology, and provides a billing method and system, and a billing server. The method includes: generating, by a PBX, billing ticket information and reporting the billing ticket information to a billing server when an incoming call from an external user to an internal user of the PBX, an outgoing call from an internal user of the PBX, or a call between internal users of the PBX occurs; receiving and storing, by the billing server, the billing ticket information reported from the PBX; initiating, by the billing server, a service connection to a billing center through the PBX, or triggering, by the billing server, a fixed wireless station to initiate a service connection to a billing center directly when the PBX system is in an idle state; and sending, by the billing server, the stored billing ticket information to the billing center after the connection is established successfully. The present invention can implement billing for internal calls within the service scope of a wireless PBX without too many modifications to the existing network equipment, and has little adverse effect on the call.