Actually if you have your loan officer get in touch with the preffered lenders loan officer, you can usally get this taken care of. If you can get your loan officer to send them DU Approval then that will usually suffice and the preffered lenders loan officer will send a preap letter.

This is also done because it is not unheard of for people to doctor up previous preapproval letters. Nor is it unheard of for shady loan officers to prequal or preapprove people who are actually not worthy of being preapproved.