To refinance with Brazos you may need a co-signer. The lender says 14.30% of approved borrowers use a co-signer. With a co-signer you'll need at least a 690 credit score and your co-signer will need at least a 720 credit score. The minimum income to apply is $30,000 with a co-signer and your co-signer must have a minimum income of $60,000.