System Identification Number Allocations

The SID (System Identification Number) is a 15 bit number (0-32,767) transmitted by base stations that identifies a wireless system that conforms to a TIA cellular or PCS standard. The SID is used by mobiles to recognize the type of system they are accessing (e.g. through the CDMA PRL). The SID may also modify some signaling messages that are transmitted by mobiles.

In the wireless network, the SID is used for billing purposes, as a unique identification of the system that is serving a mobile (and that thus must be compensated for services provided to roamers). Since it is easier to transmit a 16 bit number on a network, a new range of SID's are available for network purposes only (32,768-65,535). Some of these are used as BIDs (Billing Identifiers), and are used to discriminate between different portions of a system for accounting purposes. For GSM and LTE technologies the BID code can go as high as 99999. BIDs are assigned by CIBERNET (+1-202-785-0081).

SID codes are assigned by the national telecom regulator, a designated organization or, failing that, by IFAST if the national authority is unwilling or unable to perform this task or if the operator wants a range directly from IFAST (e.g. a mobile satellite operator).  If a country does not have a SID range, or needs a larger range, they can apply to the IFAST to have one of the reserved ranges listed below allocated. Not every country that has been assigned a SID range is actually using it (for example, GSM and NMT systems do not use the SID identifier). IFAST has been allocating SID ranges since November 1997. Prior to that, SID ranges were allocated by TIA subcommittee TR-45.2.

SID Allocation Tables

SID codes are listed alphabetically by Country and numerically. Countries marked with an asterisk are involved in a SID conflict. Either a SID assigned to that country is being used by another country, or that country is using a SID from another country. Known SID conflicts are listed.

SID Ranges.

Individual SID Code Asssignments.

Web query forms with more detailed SID (and IRM) information are available to IFAST members. Membership is free to IRM/SID assignees upon application, and costs $1000 per year to others. For more information contact .

To report  other SID conflicts please contact


                                                                                                                                                                                                       June 17 , 2021