Anyone who has ever applied for a credit card, tried to secure a loan, or even rented an apartment knows the crucial importance of having a solid credit report. And that's why a new study by the Federal Trade Commission may have millions of Americans worried. According to the FTC, one in four consumers has a "potentially material error" on one of their three credit reports, which are produced by the agencies Equifax, Experian, and TransUnion.

The FTC says only 5 percent of consumers have an error so serious that it would result in a financial setback, such as a loan rejection or higher interest rate payments. However, with 200 million Americans covered by the three agencies, that means 10 million people could be adversely affected.

"These are eye-opening numbers for American consumers," Howard Shelanski, an FTC official, said. "The results of this first-of-its-kind study make it clear that consumers should check their reports regularly. If they don't, they are potentially putting their pocketbooks at risk."

In other findings, the FTC said that one in five consumers had an error corrected after challenging the information. Of those filing a dispute, about 13 percent were able to change their credit scores, while 5 percent saw a big enough change to graduate to a lower-risk credit rating.

The credit report agencies say that only 2.2 percent of reports have an error that would move a consumer in to a higher-risk tier. "Our goal is perfection," said Equifax in a statement. "For that to happen, all parties — data furnishers, consumers, government agencies, and the [credit report agencies] — have a responsibility and need to work together."

Still, consumer advocates say it's time for the agencies undergo some serious changes. "With FTC's confirmation that credit report errors are all too common and harmful to consumers, it's high time that credit reporting agencies overhaul their operations so they actually comply with the law and investigate consumers' disputes, with actual human beings as investigators," said Evan Hendricks, author of the FTC report.