Question

If a mobile phone is lost or stolen and the original SIM card is replaced with a new one by another person, which of the following unique identifiers is most useful for tracking and identifying the physical device?

• A. 12 digit IMEI number
• B. 12 digit IMSI number
• C. 15-digit IMEI number
• D. 15-digit IMSI number

Answer 1

Answer:

C. 15-digit IMEI number

• The IMEI is a unique 15-digit hardware serial number hardcoded into the mobile device itself.

• Unlike a phone number or a SIM card, the IMEI does not change when a new SIM card is inserted.

• When the phone connects to any cellular network with a new SIM, the network provider can instantly detect the device's IMEI, making it the primary tool for law enforcement and service providers to track, locate, or block a blacklisted handset.