Fresh figures show workers are doing more overtime, many for no extra pay.
Photo: AFP
The 2015 Hays Salary Guide reveals 29 percent of firms increased workers' overtime over the past year, more than a third of them by up to 10 hours a week.
The findings are based on a survey of 451 employers, covering 374,000 members of staff.
Just over half of employers reported salaried staff were not paid extra any hours beyond the standard 40 a week.
Managing director of the recruitment agency Hays New Zealand Jason Walker said highly skilled professionals on salaries were doing a lot of the extra work.
He said 76 percent of employers expected a surge in business over the coming year, and firms should consider employing more staff to ease the pressure on workers.