Most mortgage borrowers know that underwriters look at their debt-to-income ratios when determining how much home they qualify to buy. But most don’t know that Fannie Mae and Freddie Mac give them “extra credit” for any non-taxable income they receive. According to Fannie Mae and Freddie Mac underwriting guidelines,this income can be “grossed up” or increased by 25%. Because it’s not taxable it’s worth more to you–and more to your underwriter. So whether it’s a government pension, interest on muni bonds, Social Security, child support, or whatever–make sure you tell your loan officer that the income is tax-free. And be prepared to supply documents proving it. You might find yourself able to afford more than you thought.