Well first off you're going to need to know the ESN, MEID, or IMEI of the mobile device you want to check. The information below should help get you started.
Dial *#06# on your phone to display the IMEI.
Select the Service/Provider from the drop down menu on CheckESNFree.com
Enter the IMEI shown on your phone's screen.
Submit your entry to check the status of your IMEI.
If you feel an ESN you are checking is coming back with invalid, or incorrect response, please feel free contact us anytime.