The same problems that plagued the foreclosure process — and prompted a multibillion-dollar settlement with big banks — are emerging in the debt-collection practices of credit-card companies.

As they work through a glut of bad loans, companies like American Express, Citigroup and Discover Financial are going to court to recoup their money. But many of the lawsuits rely on erroneous documents, incomplete records and generic testimony from witnesses, according to judges who oversee the cases.

Lenders, the judges said, are churning out lawsuits without regard for accuracy and improperly collecting debts from consumers.

The concerns echo a recent abuse in the foreclosure system, a practice known as robo-signing in which banks produced similar documents for different homeowners and did not review them.

"I would say that roughly 90 percent of the credit-card lawsuits are flawed and can't prove the person owes the debt," said Noach Dear, a New York state judge who said he presides over as many as 100 such cases a day.

In April, Dear dismissed a lawsuit filed by American Express, citing a lack of evidence. The American Express employee who testified, the judge noted, provided generic testimony about the way the company maintained its records.

The same witness gave similar evidence in other cases, which the judge said amounted to "robo-testimony."

American Express and other credit-card companies defended their practices. Sonya Conway, a spokeswoman for American Express, said, "we strongly disagree with Judge Dear's comments and believe that we have a strong process in place to ensure accuracy of testimony and affidavits provided to courts."

Interviews with dozens of state judges, regulators and lawyers, however, indicated that such flaws are increasingly common in credit-card suits. In certain instances, lenders are trying to collect money from consumers who have already paid their bills, or increasing the size of the debts by adding erroneous fees and interest costs.