All Sprint's phones R locked to them. Doesn't matter what Phone U HAD with them. They also are one of ONLY A VERY SMALL FEW Carriers that DO NOT UTILIZE A SIM CARD As well. I very seriously doubt that they will even UNLOCK it 4 U, if they do it would Totally surprise myself & a lot of readers of these posts here on CNET! My suggestion 2 U is 2 Fold. 1st, find a carrier that U want to go too & MAKE SURE THAT THEY CAN USE A PHONE WITH NO SIM CARD Provision. Secondly, after Sprint refuses to "Unlock" the phone, if U R Able 2 find a carrier that doesn't require a SIM CARD, as stated in above post, see if the Carrier U Find, if they can, or I should say "WILL" they re-flash the G S III 4 U. If they can't or won't, don't B surprised, as they make $$ on not just the service plans they offer, but on the Phones they sell too. BUT U STILL HAVE AN OPTION!!! It's by an Android Leader of "Un-Locking & ROOTING" Cell phones. They are XDA, not by my opinion only, but by Many Top companies. They even have an ROOT/UNLOCK GUIDE On-Line Made just 4 mine & your Galaxy S III cellphone!!! From what I've heard, if you run into any problems, that they will help U out too! First thing though U must do is find a carrier that doesn't use SIM CARDS!!! I hoped this information you find helpful, or possibly someone else reading this post. Hope its been helpful 2 U if not at least informative article!