Queensland-based cattle and meat processing company Australian Country Choice Holdings (ACCH) has entered into an enforceable undertaking (EU) with the Fair Work Ombudsman (FWO) after self-reporting the underpayments.

Staff inquiries led to an internal review that discovered workers at their abattoir and meat-processing facility in Brisbane's Cannon Hill were underpaid entitlements under several awards and enterprise agreements from 2010 to 2021.

Under the EU, the company must back pay all underpaid employees by January 13, 2023.

Individual back payments range from less than one dollar to more than $134,000.

ACCH has already repaid 342 current and former staff a total of almost $3.3 million including superannuation and interest, the FWO said.

The privately owned, family run company self-reported their non-compliance to the ombudsman in 2020.

The FWO said the underpayments occurred because companies in the Australian Country Choice Group had employees on contracts containing "unlawful and ineffective" clauses.

ACC Group companies believed the clauses let them offset entitlements by offering a higher overall pay rate, the FWO said.

It led to employees being underpaid entitlements including overtime, shift and meal allowances, public holiday penalty rates and annual leave loading.

The companies also breached record-keeping and pay slip laws.

Employees who were underpaid ranged from meat workers and cleaners to administrative and manufacturing staff.

"This matter demonstrates how important it is for employers to prioritise their compliance with workplace relations law ... ensuring the terms of employment contracts are lawful and effective and that all relevant award and agreement entitlements are passed on," Acting FWO Michael Campbell said.

"It also shows the importance of monitoring pay rates to ensure these remain in step with increasing legal minimums."

Mr Campbell said ACCH had shown a "strong commitment to rectifying underpayments".

Under the EU, ACCH is required to apologise to workers and publish statements in the media, on social media, on its website and at its workplaces detailing the breaches.

They must hire an independent expert to review their underpayment rectification process and provide a report to the FWO.

ACCH are also required to pay the Consolidated Revenue Fund $200,000 and set up a wages and entitlements hotline for employees for 12 months.

Australian Associated Press