One factor any creditor must assess before offering credit is the total debt of the person applying. If a large portion of your income each month is already committed to paying off other debt, such as credit cards, auto loans, or student loans, the lender will wonder if you may have trouble paying back a new mortgage on top of them.

As a rule of thumb, financial experts say that non-mortgage debt payments should not exceed 10-15 percent of your take home pay each month. If your debts are currently too high, consider ways to pay some down before you apply for your mortgage.