Hughes said that to curtail labor costs, his managers have asked him to punch out but remain in the store to be ready to punch back in as soon as the store gets busy.

The $28 billion company operates a small part of its more than 35,000 restaurants worldwide. Nearly 81 percent of its restaurants are run by franchisees.

"In the past, McDonald's has tried to shield itself from liability from these unlawful employment practices committed at its franchise restaurants," said Joe Sellers, one of the attorneys representing workers.

Sellers said McDonald's exerts its control over the daily operations of its franchisees by providing software, regular inspections and instructions on how to change or correct tasks, among other things.

"We believe it is time McDonald's accepts responsibility for the pay practices at its franchise restaurants," Sellers said.

All cases seek class-action status or collective-action certification. Lawyers involved in the cases said the lawsuits could affect more than 30,000 low-wage workers.