Mobile Virtual Network Operators (MVNOs) have become an integral part of the telecom industry as they fulfill the requirements of subscribers who are not satisfied with the services of MNOs. But, being an MVNO in the present-day competitive world is not easy. Many MVNOs are conceptualized with great visions and seem to work well in the beginning, but they often struggle to maintain their momentum because of one reason or another. Whatever the reason may appear on the surface, the root cause of their problem lies in the telecom billing systems they employ.