From data entry mistakes to the results of identity theft, errors on your credit report can lower your credit score. That in turn can limit your ability to qualify for favorable interest rates on loans or new credit cards.

If you monitor your credit reports on a regular basis, though, you can fix mistakes before they have a negative impact.

Here's how to check your credit report for free and what to do if you find any errors.

Which reports you need to check: 'Your Experian credit report can look very different from your TransUnion'

Your credit reports are generated by three major credit bureaus: Equifax, Experian and TransUnion. It would be a mistake to think that they're all the same, says Matt Schulz, chief credit analyst at LendingTree and author of "Ask Questions, Save Money, Make More."

Your credit reports are different because lenders can choose which bureau they want to report your activity to, and what and when to share.

"Your Experian credit report can look very different from your TransUnion credit report, which can look very different from your Equifax credit report," Schulz says. "When you go to borrow money, you don't necessarily know which of these three credit reports that lender is going to see."

That's why it's important to monitor each of your credit reports for mistakes, he says.

How to get your credit reports

The first step is to request a copy of your credit reports from each of the three bureaus.

By law, you can receive one free credit report from each major credit bureau every year by visiting annualcreditreport.com. Last year, all three major credit bureaus permanently extended a program that allows you to get your credit report for free once a week.

While you don't necessarily need to review your credit reports that often, you should aim to review quarterly or at least annually, according to Experian.

Checking your own report shouldn't have a negative impact on your score, according to the Consumer Financial Protection Bureau.

Once you obtain your credit report, look closely for errors, such as accounts that aren't yours, incorrect credit limits or unauthorized hard credit inquiries.

How to flag errors on your credit report

If you spot any mistakes, you can file a dispute for free with the credit bureau that generated the report and/or contact the business that reported the error directly. You can file disputes by mail or online here:

• Equifax
• Experian
• TransUnion

When you file a report, you'll need the following information:

• The creditor's name and account number
• The items on your credit report you think are incorrect
• The reason you believe the reported information is a mistake

You'll need to provide details including your full name, Social Security number, birthday, current address and any address you've used over the past two years.

Once you submit your dispute to one of the credit bureaus, it has 30 days to investigate, according to the Federal Trade Commission. The bureau will contact the business that reported the potential error, give it the evidence you've submitted to support your claim and instruct it to begin an investigation, per the FTC's website.

If the business concludes it made a mistake, it must notify each of the major credit bureaus so they can update your credit report accordingly. The credit bureau you submitted the claim with must get back to you with the results of the investigation.

While this may seem like a lot of work, it's worth the effort if removing errors from your credit report helps boost your credit score.

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