International Mobile Equipment Identity - in short IMEI. There's at least a few reasons to check yours!
Just look at the list below and learn what information can you get with IMEI check report:
It's possible to check your device's: model number, part number, capacity, color. This information is usually available for most popular brands.
Some information is available only via Serial Number. That is why sometimes it is neccesary to convert IMEI to SN.
It's possible to check if the phone is network locked or free. If it's locked, you will not be able to use the phone with other carriers.
LOCKED NETWORK AND COUNTRY.
Checking IMEI will tell you where the phone was bought and what country it's locked to. If it is, usually you'll need to know the correct network to unlock the phone.
ORIGINAL OR REPLACED.
Check if the IMEI is original or was replaced with illegal methods. You better check it before buying the phone that's brand new.
WARRANTY INFO AND PRODUCTION DATE.
Make sure the phone is still on warranty or if it has already expired. Check also the date it was produced.
TECHNICAL SUPPORT, REPAIRS AND SERVICE COVERAGE.
You can check if your phone is still supported and active, or if its service warranty has expired.
Check if the phone was activated with a SIM card.
This gives you information if the phone is clean or was reported as lost or stolen. This information is very important to check when buying a second hand phone. You will not be able to use blacklisted phones.
CONTRACT AND BILL STATUS.
With this you can check if your phone is still on contract and the bills were paid. Also needed when buying a used phone.
ACTIVATION LOCK STATUS.
Find out if the phone has an activation lock ON and what is the status of it - CLEAN OR LOST. Such activation lock is an option in most phones and is called a bit different for each brand.
IMPORTANT: The list contains all possibilities, included all brands and models. That means you will not be able to check all those points above for each phone brands.