Most of the time, if you have an account that has gone to collections or been written off as a bad debt, you know about it, says Rhonda Bailey, credit counselor and credit report review manager for the nonprofit Credit Counseling of Arkansas.

But not always.

"There are those few instances, like an old utility bill after you've moved, (where) the collection agency didn't find them and (the consumer) forgot about it," she says. "I see that occasionally."

If you find an item that isn't yours, you can dispute it and have it removed from your report.

If the item is yours, you have some decisions to make, Bailey says. Can you afford to pay it?

It's a good idea to check your state's statute of limitations, which is the period of time creditors have to sue you over a debt. Your state attorney general's office can give you that time limit, she says.

Separate from that time limit, the item can stay on your credit report for seven years. The longer it's been on your report, the less it affects your score.