Are you missing something? Seriously…
Do not (I repeat – DO NOT) do this under any circumstances. Even if this guy is your best friend.
Have you given any thought as to why does this person need to put the phone on someone else’s name? Why can’t he get it in his own name?
This person has obviously trashed his credit, so he can’t get a cellular contract on his name.
It’s a very bad idea to lend your credit to someone else. Especially someone you know has trashed his own credit. If he doesn’t care about his own credit, why would he care about yours?
If you put the cell phone on your name, you will be responsible for the bill, no matter how high this other person runs it up. It’s very likely that this person will run up a huge bill.
He may pay you at first or only make partial payments. In the end, he will stop making payments (this is probably how he got his credit trashed in the first place). You will be stuck with a big bill and the balance of the contract. Not to mention that your credit will be trashed in the process.
NEVER agree to lend your credit to anyone!