I had contacted Sprint to confirm that I had lost my mogal phone and since I have insurance, I got a brand new one. However, I found the lost phone, my question is simply, can this phone be used again? More specifically, can I give this phone to my brother and can he sign up for a new plan, with this phone? Thanks for the assistance everyone

I wouldn't think so as they gave you a new phone but that's just my guess.  They would probably charge you for the new phone they sent you or ever accuse you of making a false claim.  They might even ask you to send the new phone back since your other one is no longer lost.

If you filed a lost phone claim with Sprint they should have banned the ESN from being used on their network, making it useless. But if you called and told them you found it they might allow it again, but I'm not sure. I remember reading somewhere that once an ESN is banned it's banned for good.

Ive ran into this in the retail world. Basically the phone is shot until a tech creates a new ESN. My experience was with a stolen phone and somehow must have been returned to a store and then returned reflashed from a repair center. When trying to activate it, sprint said no no. After sending it back to the repair center nothing was ever fixed. I hear cloning an esn is illegal but I'm not sure how they even create esn's.