Can I sell my cell phone if I still owe money on it through a cell?
Sure. But it may not be entirely legal. Logically, if you still owe money for something, then it's not entirely your's. You could probably get away with it, as long as you pretty quickly paid the remaining balance of the lease, once you sold the phone. You may want to check with your State regarding this, since I'm pretty sure that kind of thing is governed by the State.