Checking the IMEI Number One of the most reliable ways to check if your phone is unlocked is by using its International Mobile Equipment Identity (IMEI) number.

Phone companies use the numbers to track misplaced, lost or stolen cell phones. But in the hands of law enforcement, IMEI numbers can become a powerful tool in criminal investigations.

If a phone is reported stolen, the carrier will usually blacklist the serial number, known as the IMEI number.

This displays your device's IMEI number, but in some phone models, it also includes the SIM card's ICCID number. To use this secret short code, simply launch the Phone app and type *#06#.

Next, head to the new carrier’s website and insert the IMEI number into its “bring your own phone” or “bring your own device” tool. Here are the appropriate pages for AT&T, T-Mobile, and ...

While serial numbers are often preferred if you're filing reports for lost or stolen phones, an IMEI number can be a good substitute in many instances. "Lock" becomes "Secure" Left: v2.1. Right: v2.2.

You may need to know your Android phone's model number if you're having it repaired or selling it. Here's how to find it, regardless of which Android you own.