Research has shown that up to 80 percent of credit reports contain errors; while some won’t impact your score, others can. Go to annualcreditreport.com, which lets you order a copy of your credit report for free from each of the three major credit reporting bureaus. If you’re gearing up for a big purchase — say, a house or a car — and you haven’t checked your credit in a while, order all three, says the NFCC’s Cunningham. Otherwise, it’s fine to order one at a time and space them out over the course of a year. If you do notice a mistake, contact the bureau (their websites have dispute forms) to find out if they can fix it on their end or if you need to contact the creditor to resolve the issue.