gmac mortgage payoff phone number
GMAC Mortgage Corporation makes it fairly easy to pay off a GMAC home mortgage early. Here are the steps you will need to take: 1  Call GMAC Mortgage or click Request Payoff on GMAC Mortgage's official website. 2  You can request the payoff amount by calling (800) 766-4622. 3  Have your account number and last four digits of you social security number handy.