The worker was employed as a barista in the Campbellfield cafe for three years, and received a flat hourly rate of between $17 and $19 for all hours worked.
However, under the relevant award, the employee should have been paid as much as $23.74 for ordinary hours, while weekend penalty rates would have increased that to as much as $52.23 per hour on public holidays.
That resulted in an underpayment totalling $29,061 over the duration of employment.
The underpayment came to light after the worker contacted the Fair Work Ombudsman.
Ombudsman Natalie James said the cafe owner fully co-operated and reimbursed the affected worker, once their obligations were fully explained.
It echoes similar incidents where businesses have faced hefty lump sum payments after a lack of awareness about their legal obligations as an employer has come back to bite them.
“I encourage employers to make use of the range of resources available on our website and inform themselves about their workplace obligations, and to get in touch with my agency if they need free advice,” Ms James said.
Information on employer obligations, including awards and conditions, can be found at www.fairwork.gov.au or call the Fair Work Infoline on 13 13 94.