An IMEI (International Mobile Equipment Identity) is a unique number assigned to a mobile device that helps identify that specific device on a cellular network. If you’ve searched for “what is IMEI” or “what is an IMEI number,” the simplest answer is that an IMEI identifies the device, while identifiers such as the IMSI and ICCID identify other parts of the mobile connectivity ecosystem.
What is IMEI?
The IMEI (International Mobile Equipment Identity) is a unique identifier used to identify a specific mobile device on a cellular network. Unlike the IMSI, which identifies a subscriber, the IMEI is associated with the device itself.
IMEI numbers are commonly used by mobile network operators and device manufacturers to identify and validate devices. They can also be used when reporting a device as lost or stolen or when troubleshooting device-related issues.
Understanding the IMEI Number
An IMEI is commonly represented as a 15-digit number. It contains information used to identify the mobile device, along with a final check digit used to validate the number.
The IMEI is made up of several components, including the Type Allocation Code (TAC), a device-specific serial number, and a check digit. The exact structure and terminology have evolved over time, so the format should be interpreted according to the applicable 3GPP specification.
How many digits is an IMEI?
A standard IMEI is 15 digits long. An IMEISV (IMEI Software Version) is a related 16-digit identifier that includes a software version component.
Is IMEI the same as SIM?
No. An IMEI identifies the device, while a SIM card provides the network credentials and identifiers used to connect that device to a cellular network.
A SIM card has its own identifier called an ICCID (Integrated Circuit Card Identifier). The IMEI and ICCID therefore identify different parts of the cellular connectivity ecosystem.
IMEI = device
ICCID = SIM card
Is IMEI the same as an IMSI number?
No. The IMSI (International Mobile Subscriber Identity) identifies the subscriber associated with a mobile network service, while the IMEI identifies the physical device.
The IMSI is stored as part of the SIM or subscriber profile and is used by the mobile network to identify and authenticate the subscriber. The IMEI, on the other hand, identifies the device itself.
IMSI = subscriber
IMEI = device
What is an IMEI number used for?
An IMEI number is a helpful way to track if a device is lost or stolen. Additionally, the device manufacturer or connectivity provider may need the number combination in the event of a complaint or for error analysis in support inquiries.
How to Find Your IMEI Number
There are several ways to find the IMEI number for a mobile device. Depending on the device and manufacturer, you may be able to find it using one of the following methods:
- *Dial #06#: On many mobile devices, entering *#06# in the phone’s dialer will display the IMEI.
- Check device settings: The IMEI is typically available in the device’s settings under information about the phone or device.
- Check the device or SIM tray: Some devices have the IMEI printed on the device itself or on the SIM tray.
- Check the original packaging: The IMEI may also be printed on the device’s original packaging or documentation.
For IoT deployments, organizations may also access device identifiers through their connectivity management platform, making it easier to manage IMEIs across large numbers of connected devices.
IMEI Security
In IoT deployments, managing large numbers of devices can be challenging. With ConnectivityPro™, organizations benefit from industry leading connectivity management features and functionality that allow businesses to manage and monitor their IoT network connectivity quickly and easily for advanced visibility and control. ConnectivityPro provides a simplified, streamlined, experience, enabling users to manage network connectivity from more than 24 cellular and satellite carriers via a single interface with the tools they need to provision IoT devices, prevent data overages and unnecessary costs, and diagnose connectivity issues in real time.
IMEI vs. IMSI vs. ICCID
IMEI, IMSI, and ICCID are all identifiers used in mobile connectivity, but each identifies something different.
| Identifier | What It Identifies | Associated With |
|---|---|---|
| IMEI | Device | Mobile device |
| IMSI | Subscriber | Mobile network subscription |
| ICCID | SIM | Physical SIM or eSIM |
The easiest way to remember the difference: IMEI identifies the device, IMSI identifies the subscriber, and ICCID identifies the SIM.
The International Mobile Equipment Identity, or IMEI, serves as a critical identifier for mobile devices operating within GSM networks. Its unique 15-digit composition, consisting of various components like the Type Allocation Code (TAC) and check digit, establishes it as a device’s fingerprint. This distinctive number enables GSM networks, phone carriers, law enforcement agencies, and authorized manufacturers to track and validate devices, making it an indispensable tool for locating lost or stolen devices and providing support in various scenarios.
The IMEI number’s significance lies in its role as a separate entity from the SIM card and IMSI number. While the SIM card is tied to network identification and the IMSI number serves the mobile operator’s profile data, the IMEI is specifically associated with the device itself. This distinction is pivotal in efficiently managing and troubleshooting device-related issues, streamlining error analysis, and enhancing device security.
Discovering the IMEI number is relatively straightforward, with various methods available, such as checking the packaging or looking beneath the battery cover. In the context of IoT deployments, managing large numbers of devices becomes more manageable with solutions like ConnectivityPro™. This tool offers organizations a comprehensive approach to connectivity management, ensuring IoT devices are provisioned correctly, preventing unnecessary costs, and swiftly diagnosing connectivity problems.
In essence, understanding “what is IMEI” is fundamental in comprehending the essential role this unique identifier plays in securing and managing mobile devices. Its use extends beyond mere identification, encompassing device validation, support facilitation, and enhanced security. As technology continues to evolve, the IMEI number remains a crucial element in the realm of mobile communication, ensuring devices are effectively monitored, controlled, and safeguarded.
Updated July 2026.