What is International Mobile Equipment Identity (IMSI)?
The International Mobile Equipment Identity (IMEI) is a unique 15-digit number assigned to every mobile device that connects to cellular networks, including smartphones, tablets, and IoT devices with SIM capability. The IMEI identifies the physical device itself, independent of the subscriber or SIM card, and is used by mobile network operators to distinguish valid devices from unauthorized or fraudulent ones. Its structure includes information about the device’s manufacturer, model, and a check digit for validation.
In telecommunications and security contexts, the IMEI plays an important role in device authentication, theft prevention, and fraud management. Network operators can block devices reported as stolen or compromised by adding their IMEI to a blacklist, preventing them from accessing cellular networks. From a cybersecurity and data protection perspective, IMEI data is considered sensitive, as it can be used to track devices and, indirectly, users, making its collection and handling subject to privacy and data protection regulations in many jurisdictions.