Pawned some valuables? Taken out a payday loan? Signed for a car-title loan?
Those transactions don't show up on your credit report, says Ulzheimer.
"But if you default and the lender enlists a collection agency to come after you for the balance, that action likely will go on your report," he says.
Another item that doesn't show up on credit reports is a prepaid debit card. "They are not on your credit report because they are not an extension of credit," Ulzheimer says.
Utility providers are also often missing from credit reports.
While some power, gas and phone companies routinely report to credit bureaus and as a result, show up on your credit report, more often they don't, Ulzheimer says.
That can change if you dodge a bill that goes into collections. You can probably expect that notation to end up on your report.