if you find someone who wants to use the phone on T-mobile.
Unlocking the phone may make it more desirable if you sell it on ebay or Craigslist.
I have a X2 phone that I want to sell. It's on the T-mobile network, with sim card and charger. Is there a way to unlock the phone for resale? Should I just sell the phone with the phone number already in it, locked?