International mobile subscriber identity information
ITU-T recommendation
E.212
International Mobile Subscriber Identity (IMSI)
Status
In force
Year started
1988; 36 years ago (1988)
Latest version
(09/16) September 2016
Organization
ITU-T
Committee
Study Group 2
Website
www.itu.int/rec/T-REC-E.212
The international mobile subscriber identity (IMSI; /ˈɪmziː/) is a number that uniquely identifies every user of a cellular network.[1] It is stored as a 64-bit field and is sent by the mobile device to the network. It is also used for acquiring other details of the mobile in the home location register (HLR) or as locally copied in the visitor location register. To prevent eavesdroppers from identifying and tracking the subscriber on the radio interface, the IMSI is sent as rarely as possible and a randomly-generated TMSI is sent instead.
The IMSI is used in any mobile network that interconnects with other networks. For GSM, UMTS and LTE networks, this number was provisioned in the SIM card and for cdmaOne and CDMA2000 networks, in the phone directly or in the R-UIM card (the CDMA equivalent of the SIM card). Both cards have been superseded by the UICC.
An IMSI is usually presented as a 15-digit number but can be shorter. For example, MTN South Africa's old IMSIs that are still in use in the market are 14 digits long. The first 3 digits represent the mobile country code (MCC), which is followed by the mobile network code (MNC), either 2-digit (European standard) or 3-digit (North American standard). The length of the MNC depends on the value of the MCC, and it is recommended that the length is uniform within a MCC area.[2] The remaining digits are the mobile subscription identification number (MSIN) within the network's customer base, usually 9 to 10 digits long, depending on the length of the MNC.
The IMSI conforms to the ITU E.212 numbering standard.
IMSIs can sometimes be mistaken for the ICCID (E.118), which is the identifier for the physical SIM card itself (or now the virtual SIM card if it is an eSIM). The IMSI lives as part of the profile (or one of several profiles if the SIM and operator support multi-IMSI SIMs) on the SIM/ICCID.
^"E.212 : The international identification plan for public networks and subscriptions". www.itu.int. Retrieved 2019-11-06.
^3GPP specification 23.003 Release 14.3.0 (2017-03), 2.2 "Composition of IMSI"
and 28 Related for: International mobile subscriber identity information
A SIM (SubscriberIdentity Module) card is an integrated circuit (IC) intended to securely store an internationalmobilesubscriberidentity (IMSI) number...
Subscriber Directory Number". The MSISDN and internationalmobilesubscriberidentity (IMSI) are two important numbers used for identifying a mobile subscriber...
a mobile phone, which is the last part of the internationalmobilesubscriberidentity (IMSI). The MIN is a number that uniquely identifies a mobile phone...
for one reason or another. At that point, the global "internationalmobilesubscriberidentity" (IMSI) must be sent to the network. The IMSI is sent as...
HLRs per public land mobile network (PLMN), though one internationalmobilesubscriberidentity (IMSI)/MSISDN pair can be associated with only one logical...
in Wiktionary, the free dictionary. IMSI may refer to: Internationalmobilesubscriberidentity Intracytoplasmic morphologically selected sperm injection...
telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone...
(255 bytes maximum per message) IMSI (internationalmobilesubscriber identifier) TMSI (temporary mobilesubscriber identifier, for position security) UIMID...
in a cellular phone that stores the telephone number, internationalmobilesubscriberidentity and an Electronic Serial Number. Phones with dual- or multi-NAM...
A Maritime Mobile Service Identity (MMSI) is effectively a maritime object's international maritime telephone number, a temporarily assigned UID issued...
accept only SIM cards with certain InternationalMobileSubscriberIdentities (IMSIs); IMSIs may be restricted by: Mobile country code (MCC; e.g., will only...
phones) by requiring them to authenticate using internationalmobilesubscriberidentity (IMSI). International regulations no longer require a call sign for...
Identifier between GPRS Support Nodes (GSNs). The user identity (InternationalMobileSubscriberIdentity (IMSI)) and the application identifier (NSAPI) are...
basis, which excluded people with poor credit. Prepaid mobile service was invented by Subscriber Computing, Inc., an Orange County company, (1986–1998)...
features available over the Global System for Mobile Communications (GSM) to mobile phone subscribers all over the world. The GSM standards are defined...
(PLMN). This internationally unique identifier is used for location updating of mobilesubscribers. It is composed of a three decimal digit mobile country...
Subscriberidentity module (SIM) cards and removable user identity module (R-UIM) cards. A hardware notification LED on some phones Low-end mobile phones...
or UTRAN), the core network (Mobile Application Part, or MAP) and the authentication of users via SIM (subscriberidentity module) cards. The technology...
protocol allowing service providers to obtain a mobile (digital) signature from a mobile phone subscriber. In 2001, mSign gained industry-wide coverage...
Browser leaks sensitive data like internationalmobilesubscriberidentities, internationalmobile station equipment identities, MSISDN's, Android ID's, MAC...