Abstract: Telecom Industry is based upon user satisfaction and user services. Mobile operators provide VAS (Value Added Services) to users to increase revenue and promote their services. Now a days, OTA (Over the Air) technology to update services on CARD without physically interacting CARDs. This requires implementation of different components of OTA technology to be able to perform such activities seamlessly. This paper discusses this implementation of OTA in terms of RESTful web services by removing the complex component implementation of OTA technology and creating maintainable, scalable, reusable modular services for different operations on a SIM card.