If you’ve found a mistake in your credit report, you are in good company.

A long-awaited report by the Federal Trade Commission has found that up to 21 percent of consumers had verified errors in their credit reports. Five percent found bloopers serious enough to not just change their credit score but also change their class of credit risk, potentially making loans more expensive or even cutting off credit access altogether.

Given that 200 million people are on file with the country’s major credit reporting bureaus, 5 percent represents about 10 million people with significant errors in their credit reports.

FTC Chairman Jon Leibowitz called the error rates “pretty troubling information” while discussing the report Sunday on CBS’s “60 Minutes.” The report came out Monday, and the agency urged people to check over their credit reports for free at annualcreditreport.com.

Two national consumer groups issued a joint statement Monday calling for industry reforms. Chi Chi Wu, staff attorney at the National Consumer Law Center, called the error rates “unconscionable.” Ed Mierzwinski at the U.S. Public Interest Research Group said the level of mistakes found by the FTC is significantly higher than the 0.5 percent error rate found in a May 2011 industry-funded study on credit-report accuracy.

“We’ve criticized the credit reporting industry for decades over unacceptable levels of seriously damaging mistakes, many of which are entirely preventable,” Mierzwinski said.

An industry group that represents the country’s big three credit reporting agencies — Experian, Equifax and TransUnion — said it considers the 5 percent figure the most important measure since it represents “material errors” that cost consumers in the marketplace. That number is low, it said.

“We’re not satisfied, but we’re working off some pretty good numbers here,” said Stuart Pratt, head of the Consumer Data Industry Association. “We want to push that error rate down further.”

Gerry Tschopp, a spokesman for Experian in Costa Mesa, Calif., said the report confirms that credit reports are “predominately accurate and serving lenders and consumers well.”

“The report shows that the vast majority of errors on credit reports have no bearing on credit scores, for example outdated information on a consumer’s phone number or address,” Tschopp said.

“We take all errors seriously, and invest millions of dollars every year in ways to maintain the integrity of our data by updating our systems to keep data as fresh and accurate as possible,” he said.

The FTC report was mandated by Congress years ago. and while the FTC issued four run-up reports to this one, the study out Monday was the first to provide concrete results on accuracy. Another report to Congress is due in 2014.

The study was based on a representative sample of 1,001 consumers who reviewed nearly 3,000 credit reports, or about three reports per person, along with a study associate. All the credit reports with alleged material errors were sent to an analyst at Fair Isaac Corp. for an initial rescoring.

Incorrect balances

The most common errors — nearly half — involved consumer accounts, such as reports showing the wrong balances on accounts, marking accounts that are closed as open, or marking payments that were on time as late.

The next most-common error involved debt collection, such as showing a bill to be in collection when a consumer says it’s been paid.

About 78 percent of the 262 people who filed disputes over a potentially material mistake on their credit report got their report modified in some way by one of the bureaus, but only 37 percent of the 262 got a modification that completely resolved the dispute.

Of 211 credit reports where there was a dispute and a credit score was ultimately changed, 29 percent had a score change of more than 25 points.

The Dodd-Frank financial reform act gave the newly created Consumer Financial Protection Bureau enforcement authority over the credit bureaus, along with the FTC.

Most people ignore reports

Richard Cordray, head of the consumer finance watchdog agency, has highlighted accuracy as a key area of concern. In December his agency released its own analysis of credit reports, noting that they are dominated by information supplied by the credit card industry and that fewer than one in five people get copies of their credit reports each year.

Wu, at the National Consumer Law Center, said her group is pushing for a number of reforms, such as requiring stricter matching criteria when credit bureaus collect data from mortgage lenders, debt collectors, credit card issuers and public records and put the information into a consumer’s credit report.

Wu said credit reporting agencies should actually perform the meaningful investigations they are required to pursue when consumers report errors.

Right now, she said, the credit bureaus turn mistakes into two- or three-digit codes with a line of text and send them to whoever supplied the information, such as a debt collector, and typically accept whatever the supplier tells them.

“It’s a travesty,” Wu said. “That has been very high on our list of necessary reforms.”