Long story, but a friend of mine bought a Sprint iPhone 5S to repair and resell. He ended up not repairing it for whatever reason, and sold it to me to repair and sell. I did, but now I'm having issues with the people who purchased it from me. Or, rather, they're having issues with the phone I sold to them. Story: The iPhone 5S is a Sprint phone. I called Sprint and made sure it had a clean ESN, wasn't blacklisted, and was ready to be activated on an account if need be. All was good. I sold to this family and they apparently want to use the iPhone on Ting, which is a carrier that uses Sprint towers and Sprint phones. They're telling me that it's not working, and they're saying that I need to call Sprint and have them "unlock" the phone.. I think Ting uses Sprint phones regardless? But apparently Ting and Sprint both said I would need to have the phone unlocked. The thing is, how am I able to have the phone unlocked when I don't have a Sprint account? Few big questions 1.) If I find someone with a Sprint account, would they be able to call and have it unlocked? Even though the phone was never on their account? 2.) Why can't Sprint check the unlock eligibility by the phone itself? It seems like an endless loop to say that they can't unlock a phone that wasn't used on the account, but they can't check what account it was used on, either. I don't want to leave this buyer without options, but I have no idea what needs to be done in this situation.