An analog telephone adapter (ATA) having a subscriber identity component in the format of a Subscriber Identity Module (SIM) that couples a telephone to a cellular network via Voice over Internet Protocol (VoIP), thereby allowing a cellular service provider to provide an alternative communication service for the home or business. Instead of using the plain old telephone service, a subscriber can plug their analog telephone into the SIM-enabled ATA (SIM-ATA) and receive telephone service from a cellular service provider, eliminating or reducing the need for a traditional Local Exchange Carrier. The SIM-ATA converts signals from analog to digital, and vice-versa. Once the analog telephone signal has been converted to digital, an IP-based protocol (e.g., VoIP) can be used to transmit the telephone call over a digital network. The cellular service provider can then track usage and bill the subscriber accordingly.