Boston Gal's Open Wallet

When Rich McEldowney of Bozeman, Mont., and his wife, Phoebe, applied for a mortgage in February 2007, their mortgage broker told them that his wife didn't have a credit score anymore. Among the reasons: They had paid off their auto loan several years ago, and she didn't have any credit cards. In fact, except for a credit card that Mr. McEldowney uses for his job as an ecologist, he and his wife don't use credit cards, preferring instead to use their debit cards and pay for things with cash or checks.

"It seems like the more debt you have, the easier it is to get credit," says Mr. McEldowney. "We don't have credit cards, and we try to be responsible with our debt."

Engineering a Credit Score

On their broker's suggestion, they turned to Pay Rent, Build Credit Inc., also known as PRBC, a credit bureau in Annapolis, Md., that specializes in collecting rental and bill-payment data. It studied Ms. McEldowney's history of paying other household bills -- such as rent, telephone, and auto insurance and her daughter's day-care bills.

She ultimately received a decent credit score. As a result, the McEldowneys were able to qualify for a 6.5% rate on a $350,000 mortgage -- roughly half a percentage point lower than the rate that Mr. McEldowney says he would have been able to get on his own.