A new government report says as many as 42 million Americans, that’s one in five, have mistakes on their credit reports.

So, what can you do to spot mistakes?

The time to review your credit report is before you get confronted with a red flag. Negative information stays on a credit report for seven years, and bankruptcies for up to ten

And that information could influence the interest you pay on everything from credit cards to car loans or whether you get those loans at all.

If you haven’t looked in awhile, your credit report includes current and previous addresses, credit accounts and any late or skipped payments, if you’ve ever been sued or arrested, and bankruptcy filings.

The Fair Credit Reporting Act entitles each consumer to an annual copy of his or her credit report from each of the three major reporting agencies. To maximize the benefits, stagger the three requests throughout the year.

Scan reports for things that could be dragging down your credit score. That can include open lines of credit that you’re not using or thought you closed, addresses where you’ve never lived or that look suspicious, and credit inquiries that you didn’t make.

If you find an error, start by contacting the consumer reporting company that compiled the report. They’re required to investigate within 30 days.

The Consumer Data Industry Association is hitting back, saying 98% of credit reports are accurate.