Can we use a customer’s middle and last name on loan documents (that is the name they have used all of their life-all their credit is listed this way on the bureau and their driver’s license)? But then use their complete legal name on the Mortgage? Or should we make sure the name is the same on all loan documents and Mortgage?

Go with your option two. Make sure the name is the same on all loan documents including the mortgage. Put a name affidavit in the file to cover the birth certificate name vs the middle/last name combo they've used all their life.

Would it be appropriate to use the name on the birth certificate then or the name on the social security card?

Now you're throwing the birth certificate and the ss card into the mix too? I think you're carrying your CIP out too far because it's only muddying the waters. Why do you need the birth certificate & ss card? You said the borrower uses middle and last on everything. You've got a driver's license, pay stubs and cbr to support that so go with it.

btw, if this is a refi you've got a whole different kettle of crawfish to deal with. You need to go with the name that's on the deed, not anything you've gotten for CIP.

Truffle is right, you must take title like you are in title on a refinance OR insert the AKA language on the face of the Mtg/DOT to show a different styling of his name. A Name Affidavit would tie all this together.

Rules, I was trained NEVER to do an aka. The borrower has one name and that's that. Name affidavits exist to cover any other names the borrower might use..

The only thing I'll ever put on a mortgage/deed of trust is an f/k/a for a recently married or divorced person who currently appears on title in their former name. That's to forge a connecting link on the chain of title.