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ATIS Assumes Management of IMSI Database

ATIS Assumes Management of IMSI Database

ATIS and the International Mobile Subscriber Identity (IMSI) Oversight Council (IOC) are pleased to announce that effective December 13, 2022, ATIS has assumed responsibility for the administration of the IMSI resource, including Home Network Identifiers (HNI) for non-CBRS spectrum users, and shared HNI four-digit IMSI Block Numbers (IBN) for CBRS spectrum users. The IMSI Code is the 15-digit number used within mobile phones that allows service operators to identify mobile terminals for purposes of international roaming and the IBN is used to identify CBRS operations, thus conserving HNI resources.

The IOC is responsible for the management and administration of IMSI in the United States and maintains compliance with the “IMSI Assignment Guidelines and Procedures” to ensure that it meets the evolving needs of the U.S. wireless telecommunications industry.

“ATIS has a long-standing track record of administering industry databases, such as the IMSI resource,” said ATIS President and CEO Susan Miller.  “Our work with the IMSI code made the use of CBRS spectrum possible. On behalf of the industry, ATIS is pleased to oversee this very important database.”

Applications for HNIs and IBNs can be submitted at

Marcella Wolfe, Manager – Public Relations and Marketing Communications, ATIS