The invention provides systems and methods providing independent determinations of services provided to be utilized in detection of fraud. According to a preferred embodiment, a call data record server is provided in communication with a prepaid calling system such that account refill/credit information is provided to the call data record server. The call data record server is also preferably in communication with systems providing subscriber services, such as a cellular service network, such that data regarding services utilized are provided to the call data record server. Using the refill/credit data and raw subscriber service data preferred embodiments of the present invention may independently determine prepaid services utilized by subscribers. Fraud may be detected from these independent determinations of the preferred embodiment by comparing a determined account balance to a selected threshold value and/or by comparing the determined account balance to that of the prepaid calling system.