Credit Score

• Mortgage lenders today rely heavily on your three-digit credit score when determining whether you qualify for a mortgage loan and at what interest rates. In general, lenders save their best interest rates for those borrowers with credit scores of 740 or higher on the popular FICO credit-scoring scale. Be warned that if you are signing your mortgage loan with a co-borrower, your lender will run your co-borrower's credit score, too. This can be a positive if your co-borrower has a higher score than you; the fact that your co-borrower has had a history of making payments on time could ease any concerns your lender has about your score. But if your co-borrower's score is too low, it could boost the interest rate that your mortgage lender assigns to your loan.
  
  

Debt-to-Income Ratio

• Most lenders want your monthly debt obligations -- a figure that includes your estimated mortgage payments -- to equal no more than 36 percent of your gross monthly income. This is where a co-borrower can help; your lender will total both your gross monthly income with your co-borrower's to determine exactly how much income your household will bring in each month. However, if your co-borrower brings a lot of debt to the equation, your lender will factor that into the debt-to-income ratio, too.
  
  

Employment Status

• Lenders prefer that you have worked in the same job, with the same company, for at least three years. This provides lenders with at least some reassurance that you are not as likely to lose your job after taking on the financial responsibility of mortgage payments each month. With a co-borrower, your lender will consider both borrowers' job histories when deciding how stable your combined gross monthly income is. If your co-borrower just started a new job, this may make your lender hesitate before approving your loan application.
  
  

Negative Judgments

• It's not easy getting a home loan if you have recent foreclosures, bankruptcies or other negative judgments in your past. This same holds true for your co-borrower; if this person has a history filled with negative judgments, your lender might either increase your interest rate or deny your loan application. However, if your co-borrower has a financial history clean of any negative judgments, it will help you case for a mortgage loan.