Jonathon Washington was 15 when he started working at McDonald's, and like most young workers, said he was not fully aware of his workplace rights.
"You really do trust your employer to have your back and make sure that you are safe and everything else," Mr Washington said.
"As far as being safe goes, they provided that, and I feel like they just could have informed employees a little bit more about what entitlements they had."
He said McDonald's inconsistently applied break rules in the three years he worked for the company and at times denied him 10-minute breaks.
Mr Washington is one of hundreds of thousands of Australians employed by McDonald's over the past six years who the fast-food worker union alleges were not given paid 10-minute breaks.
The details are included in a statement of claim lodged by the Shop, Distributive and Allied Employees Association (SDA), against McDonald's this month.
The union claim alleges a "serious contravention" of workplace rights that were part of a "systematic pattern of conduct".
SDA head Josh Peak said 350 workers were involved in the Federal Court action, with the union seeking $100 million in back pay.
He said employees were told their breaks were cumulated over their shifts, with each drink or toilet stop counting towards worker's break time.
"When they were told 'you can go to the toilet or get a drink and therefore you're not entitled to the 10-minute break', many young workers just accept that because they don't think they'd be getting deliberately lied to by their franchisees or by McDonald's Corporation itself," Mr Peak said.
"McDonald's should have done better, they can do better.
"What's shocking about this is this is some of our most vulnerable workers.
"McDonald's is the largest employer of young Australians in the country."
Under the Fast Food Award, workers must receive a paid 10-minute break if they work for four hours or more, and two 10-minute paid breaks if they work for more than nine hours.
Mr Peak said the workers joining the Federal Court action were employed at 72 company-owned sites across Australia.
The court action is the ninth of its type launched by the SDA, with franchisees previously in the union's crosshairs.
Now, the union has lodged legal action against multinational parent company McDonald's, which owns 15 per cent of its stores in Australia.
A McDonald's spokeswoman told the ABC it believed its restaurants complied with workplace laws by providing rest breaks to its employees.
"We are very mindful of our obligations under applicable employment laws, including the former enterprise agreement and the Fast Food Industry Award, and we continue to work closely with our restaurants to ensure employees receive all correct workplace entitlements and pay," she said in a statement.
"The present claim is both surprising and disappointing.
"We value our employees highly and the great contribution they make to the success of the business.
"Accordingly, McDonald's Australia intends to fully defend the claim."
A hearing date is yet to be set by the court.
