Some lawmakers, judges and regulators are trying to rein in the U.S. debt-collection industry's use of arrest warrants to recoup money owed by borrowers who are behind on credit-card payments, auto loans and other bills.

More than a third of all U.S. states allow borrowers who can't or won't pay to be jailed. Judges have signed off on more than 5,000 such warrants since the start of 2010 in nine counties with a total population of 13.6 million people, according to a tally by The Wall Street Journal of filings in those counties. Nationwide figures aren't known because many courts don't keep track of warrants by alleged offense. In interviews, 20 judges across the nation said the number of borrowers threatened with arrest in their courtrooms has surged since the financial crisis began.

The backlash is a reaction to sloppy, incomplete or even false documentation that can result in borrowers having no idea before being locked up that they were sued to collect an outstanding debt. The debt-collection industry says such errors are extremely rare, adding that warrants usually are sought only after all other efforts to persuade borrowers to pay have failed.

Earlier this month, Washington state's House of Representatives passed by a 98-0 vote a bill that would require companies to provide proof a borrower has been notified about lawsuits against them before a judge could issue an arrest warrant. All 42 Republicans voted for the legislation, which is expected to pass the state's Senate and be signed into law by the governor. A trade group representing debt collectors supports the bill and says the changes are needed because some companies are abusing Washington's existing law by improperly arresting borrowers.

In Florida, training this week for dozens of new judges and sitting judges who are moving to courts with the power to lock up borrowers includes a session about potential abuses of debt-related warrants. "Before we take away a person's freedom, we want to ensure that there are procedural safeguards," said Peter Evans, a Palm Beach County, Fla., state-court judge who proposed the session.