When a mortgage broker fishes for your credit score, you get a number back -- like 687 -- and a list of "key factors" behind that number. Obviously some key factors, like "insufficient length of credit history," which showed up on one of my reports -- you can't do much about. The fastest factor to knock down is the one that shows what level of revolving debt you're using. If you have a Visa or a MasterCard with a limit, and you're not paying it off in full every month, you're getting penalized for carrying that balance. Even knocking the balance down from 40% of your cap to 24% should help pop your score a little. The advanced tip -- which I'd like John to weigh in on since this is his area -- is that you can be penalized for using part of your cap even when there theoretically isn't a cap. There's more in this great Ken Harney column here: