If I have a co-signer, is the average of the two people's credit scores used for pre-approval?

Typically not.Just the co-signers credit is used.I would suggest you pay for the mortgage yourself with a check for the first 12 or 24 months. Then you can prove to an underwriter that all the payments were on time and might be able to get the mortgage put in your name and take advantage of the good payment history showing up on your credit afterwards.

No.. Lenders take the lowest MID score of ALL borrowers.. so if mom and dad cosign for daughter, and mom and dad have 790 scores but daughter has 620, then loan pricing and eligibility will be based on the daughters 620 score. I'm a Broker here in Scottsdale AZ and I only lend in Arizona. If you or someone you know is looking for financing options, feel free to contact me or pass along my information. William J. Acres, Lender411's number ONE lender in Arizona. 480-287-5714 WilliamAcres.com NMLS# 226347