Practically every phone has one. In fact, every device that uses cellular data, inlcuding tablets, hotspots, and cellular routers, has one as long as there’s a SIM card in there somewhere. It’s an IMEI, and it’s a really important part of the way your cellular devices work.
IMEI stands for…
“International Mobile Equipment Identity.” It’s a unique number that’s assigned to every device that has a celluar radio, as long as it conforms to the 3GPP standards. Practically every phone made today does, but very few older phones don’t. Phones that don’t use a SIM card don’t need an IMEI but sometimes have one anyway.
Think of the IMEI as your “real phone number.” The number that’s given to you from the cell company can be moved from device to device. Of course it can, or you’d need to change phone numbers every time you get a new phone. But the IMEI on your phone isn’t on any other device, ever. It stays with that phone and is never reused.
IMEI is useful because…
When you make a cell phone call, the network needs to know where to send the call. Somewhere between your carrier and any other phone company that’s involved, someone uses a table to look up which phone number is connected to which IMEI. Your phone broadcasts its IMEI to a cell tower. The cell tower sends out a message to the network any time your phone connects to it. And the call is routed, in a tiny fraction of a second. All because of the IMEI which makes it all possible.
IMEI stops criminals because…
Since every cell phone has a unique number, you can report your phone as stolen and the cell company can permanently disable it. Once a carrier has “blacklisted” an IMEI it’s not ever going to be usable again. Cellular carriers share IMEI blacklists so a phone with a bad IMEI isn’t going to be usable anywhere on the planet within a very short period of time. It’s practically impossible to change a phone’s IMEI, so the problem stops there.
How to find the IMEI on your phone
Once upon a time, up until about six years ago, phone makers put the IMEI on the back of the phone or inside the battery cover. The government required them to do it. Apple and Google didn’t like that. They said it made the phone ugly, but really they just didn’t want to take the extra step of externally labeling each phone.
So now, you can only find the IMEI by looking through the phone’s menus. (If you still sync your phone to your PC, you can get it that way too, but I don’t think anyone does that anymore.)
On an iPhone, go to the Settings app, choose General, then About. Scroll down and you’ll find the IMEI there.
On an Android phone, go to the Settings app, choose About phone, then Status.