IMEI number is used to identify your mobile device, it means that you can use it to find exact information about your phone. You can also use IMEI to blacklist your device and lock it out of the network when it gets stolen, so you should always have your IMEI number memorized becouse its very usefull.
How to find IMEI number of BlackBerry smartphone? Below you can find several methods.
Using the Dial Pad The fastet way of finding IMEI is to type *#06# in the dialing field, instantly after you do that IMEI number will pop up on your screen (or multiple numbers if your phone supports more than one SIM card)
In the phone menu Go to phone Settings and then System -> About phone -> Status -> IMEI information.
On the box If you still have the iriginal Blackberry box, you can find IMEI number affixed to it.
Below you will find a video showing how to check IMEI number on the example of BlackBerry KeyOne.