In the ever-evolving landscape of telecommunications, postpaid Interactive Voice Response (IVR) services have become an integral part of the customer experience. The United States, as a major player in the global telecom industry, has witnessed the evolution of these services, aided by advanced Operational Support Systems (OSS) and Business Support Systems (BSS). This article delves into the significance of postpaid IVR services in the USA and their seamless integration with OSS and BSS systems.