IMSI

Technology & Computing abbreviation · Telecom

IMSI
Stands forInternational Mobile Subscriber Identity
CategoriesTechnology & Computing

IMSI stands for International Mobile Subscriber Identity, a telecom abbreviation.

Unique number of up to 15 digits stored on a SIM card that identifies a mobile subscriber to the network, made up of a country code, a network code and a subscriber number. Users rarely see it.

Example: The roaming partner recognized the visitor's home network from the first five digits of the IMSI.

Usage notes

An IMSI begins with the three-digit Mobile Country Code (MCC), such as 310 to 316 for the United States, followed by a two- or three-digit Mobile Network Code (MNC). Surveillance devices called IMSI catchers, or Stingrays, imitate cell towers to collect IMSIs and track phones. 5G networks conceal the IMSI by sending an encrypted version called the SUCI.

More telecom abbreviations

  • GSMA – GSM Association
  • HFC – Hybrid fiber-coaxial
  • HSPA – High Speed Packet Access
  • ICCID – Integrated Circuit Card Identifier
  • IMEI – International Mobile Equipment Identity
  • IMS – IP Multimedia Subsystem
  • ISDN – Integrated Services Digital Network
  • IVR – Interactive voice response
  • LEO – Low Earth orbit
  • LTE – Long Term Evolution
  • LTE-A – LTE-Advanced
  • LTE-M – LTE for machines (LTE Cat-M1)

See all 114 telecom abbreviations →