The Roaming Zone
System Identification Numbers, or SID, are numeric identifiers used by cellular systems to specify the home system of a wireless carrier, and by the cellular device to determine its roaming status. Our lists are updated as changes are discovered. Some entries are in the name of the legal office that represents the wireless carrier. Administration of SID's is maintained in the private sector, not by the FCC.

FCC's Administration of Cellular SID's:
The administration of Cellular SID's was transferred to the private sector on October 1, 2003. With the transfer of this responsibility, the SID was removed from the cellular license. Cellular licensees seeking a new SID assignment, an additional SID assignment, or licensees that have ceased using an assigned SID, will be required to make their request / notification through one of the recognized SID Administrators to perform Cellular SID administration. Each organization will operate under the general guidelines developed by the FCC and the cellular industry.

These lists are presented 'as is' and we cannot guarantee their accuracy.