“We tried to preserve a reasonable balance,” said Mr. Wetzler, now a director at the firm Deloitte Tax. “We wanted to avoid imposing onerous burdens on people just for us to collect small amounts of revenue.”

But now states have greater access to data warehouses that help them better track taxes owed. Real estate transactions, federal data from the Internal Revenue Service, commercial license plates, traffic tickets, bids for government construction projects — all this information, newly digitized and dumped into a computer system, can help states find tax scofflaws.

“We’re sort of getting into ‘1984’ land here,” said Kenneth T. Zemsky, an accountant and partner at Ernst & Young. “A lot of the reason they went after athletes and entertainers is that they couldn’t find the other people. Now they’re able to get those people, too.”

Still, perhaps the best enforcement mechanism may be requiring companies to withhold additional taxes from their employees’ paychecks. State auditors may not be able to monitor every border-crossing, but with corporate payroll managers as their enforcers, they don’t need to.

“Our employees call me the ‘Tax Nazi,’ ” says Dee Nelson, the corporate payroll manager at the Koniag Development Corporation, a government contractor that works on military projects. “They get really angry at me when we withhold their pay if they do a project in Utah or wherever. And I have to explain this is the law, not me just trying to be a bully.”

Ms. Nelson’s employer is based in Anchorage, but at any given time its employees are generally working in five states with five different withholding requirements. She estimates that the administrative work required for managing multistate employees adds about 10 percent to the cost of each project.

Many Fortune 500 companies contacted for this article privately acknowledged having been slightly less vigilant than Ms. Nelson about tracking the minute-by-minute movements of their thousands of employees in the past. But these companies also say that they have been subjected to payroll audits more frequently in the last few years and that tax officials have requested travel logs for highly paid employees during these audits.