You cannot use a PIN code that is in someone else's name. People seem to frequently get PINS that are addressed to other family members that they have traveled with before and they are unable to use them. It has to be your name, at your address.
It's a combination of your name and address that identifies you, so unless you have 2 Bob Smiths at your house, any old Bob Smith is not going to be able to use a different Bob Smith's PIN.