The Fair Work Ombudsman's 2020/21 annual report has revealed the staggering amount recovered for 69,700 employees across the nation.

It represents a 20 per cent increase on the previous year and is five times the amount retrieved from employers in 2017/18.

Major companies self-reporting wage underpayments accounted for more than $100 million in recovered pay.

The report found complacency was a major factor with some firms using outdated manual processes to record hours and others failing to apply enterprise agreements to employees covered.

Other reasons behind not paying workers properly included having no accountability checks for payroll systems and the failure of senior leaders to treat wage compliance as a serious risk.

Ombudsman Sandra Parker said some of Australia's biggest companies had come forward to disclose breaches over the past two financial years.

"Underpayments by large corporate entities have become a significant issue of public concern," she wrote.

"We engage with these entities to provide assurance to underpaid employees and the community that backpayments are made and that corrective action is implemented by the company to prevent further underpayments."

The watchdog also targeted fast food, restaurants and cafes, horticulture, franchises and sham contracting.

Hospitality remains the sector with the highest disputes, making up for 36 per cent of all anonymous tips during the past financial year.

The ombudsman recovered $852,120 in unpaid JobKeeper wage subsidies for 308 workers.

Australian Associated Press