How do you complete the ABAD when the provider you're referring someone to is a Mortgage Lender and the service they will be providing is underwriting and funding the loan? Also, how do you estimate the charge or range of charges for such a service?

You should state that the services rendered are underwriting and funding. It sounds silly, especially with the sentence about other vendors being available (not if you want a loan from this lender!) but it is the way it must be completed. If the affiliate is also documented and closing you would state that as well.

I have to check my old info from when I was involved with a similar situation to see how we handled fees. I believe we stated the lenders application and origination fees here, whatever fee the lender was keeping (not turning over to a third party).

Perhaps someone else can jump in and add to this.