The present invention provides a method for providing roaming services to an HPMN's prepaid subscriber. The method includes facilitating the prepaid subscriber's registration at a VPMN by an SG, despite absence of the prepaid subscriber's roaming profile at an HPMN HLR. The HPMN and the VPMN are part of one or more partner networks and are unable to support IN protocol/agreement. The SG is deployed at either the HPMN, or an HPMN's MVNO, or a hub operator. The method further includes enabling mobile communication of the prepaid subscriber in the VPMN by the SG that converts protocol of all signaling messages, corresponding to the prepaid subscriber, into a format compatible with the HPMN. The method further includes billing the prepaid subscriber based on pre-defined criteria by using the SG that interfaces with an HPMN PPS via either: an HPMN SCP, or an HPMN service node, or an HPMN SMSC.