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(also International Mobile Equipment Identity)

IMEI definition

International Mobile Equipment Identity, or IMEI, is a code that every mobile device has. The IMEI code is 15 to 17 digits long and used to identify mobile phones. Each mobile phone has its own unique IMEI code, and most phones have one such code. However, phones with a dual SIM option have two different IMEI codes.

GSM networks use the IMEI code to identify mobile devices. Thus, the IMEI code can also be used to block stolen phones and prevent them from accessing the network in a specific country.

The IMEI code is not related to the SIM card, so even if a user changes phone numbers and uses another SIM card, the IMEI code of the mobile device will remain the same. The IMEI code is not stored on the SIM card. Instead, it’s stored inside the phone, either in the software, the SIM card slot, or both.

See also: data validation, digital identity

IMEI format

Most IMEI codes look like this: AA-BBBBBB-CCCCCC-D, where:

  • AA shows the Reporting Body Identifier, indicating the organization that allocated the TAC (Type Allocation Code) of the device.
  • BBBBBB represents the remaining digits of the TAC, which uniquely identify the device model or type.
  • CCCCCC shows the serial sequence of the mobile phone or device model.
  • D is an algorithm that serves to validate the ID number of a device.