Digging out of debt keeps getting harder for the unemployed as more companies use detailed credit checks to screen job prospects.

Out of work since December, Juan Ochoa was delighted when a staffing firm recently responded to his posting on Hotjobs.com with an opening for a data entry clerk. Before he could do much more, though, the firm checked his credit history.

The interest vanished. There were too many collections claims against him, the firm said.

“I never knew that nowadays they were going to start pulling credit checks on you even before you go for an interview,” said Mr. Ochoa, 46, who lost his job in December tracking inventory at a mining company in Santa Fe Springs, Calif. “Why would they need to pull a credit report? They’d need something like that if you were applying at a bank.”

Once reserved for government jobs or payroll positions that could involve significant sums of money, credit checks are now fast, cheap and used for all manner of work. Employers, often winnowing a big pool of job applicants in days of nearly 10 percent unemployment, view the credit check as a valuable tool for assessing someone’s judgment.