CLEVELAND -- Have you received your first credit card bills from Christmas yet? Experts say the beginning of the year is the best time to assess your credit.

In fact, Five On Your Side Troubleshooter Chris Caswell said that if you don't do a credit checkup, you may be in for a rude awakening.

Mistakes do happen, and mistakes on a credit report can cost you. So consumers are encouraged to call and get their credit report.

Debra Waite thought that the state of her credit was fine. That was before she ordered her credit reports as part of a study for Consumer Reports magazine.

"According to one of the reports, I owed (more than) $2,500 on an account that wasn't even mine," Waite said.

Waite has seen firsthand how mistakes on a credit report can have a big impact.

"I was applying for a pre-approved mortgage loan, and I believe I got turned down because of this $2,500 debt (that) wasn't mine," she said.

Consumer Reports' Tobie Stanger reviewed more than 60 reports. She said that mistakes, which can happen for any number of reasons, are fairly common. That's why it's so important to check your credit once a year.

"We found that half of the reports had some sort of inaccuracy that could potentially affect how a creditor views your credit worthiness," Stanger said.

To check your credit, there are three names that consumers need to know -- Equifax, Experian and Trans Union, the three big credit-reporting companies.

"A creditor may only report to one of the three companies, so to get a complete picture of your credit history, you need reports from all three companies," Stanger said.

Waite corrected the error on her credit report, and she now plans to check with all three companies once a year.

For a credit report, call the three major credit-reporting agencies: Equifax at (800) 685-1111, Experian at (800) 333-4930 and Trans Union at (800) 888-4213.

You may also check out their Web sites. Click on experian.com, transunion.com and equifax.com. You may even be entitled to a free report.