My mom died. My dad wants to put bill in his name. Needs to drop her line and keep the two other lines he has. What does he need to do?

They might penalize you

Will they need to keep the Death Certificate or can they make a copy? He only got 3 copies of the Death Certificate.

That is a very good idea. Have him take the bill, death certificate his valid driver's license and cell phone to the Verizon store. I am sure they can help him.