By the 9th U.S. Circuit Court of Appeals' ruling, a lower court must further consider claims raised by attorney Daniel Makanjuola that the companies set monopoly prices and engaged in anticompetitive behavior.
The decision could lead to substantial damages and a possible injunction on in-app purchase practices of the two tech giants if Makanjuola's lawsuit eventually succeeds, though the case faces multiple hurdles.
For Makanjuola, a Los Angeles attorney who has a history of suing major corporations, the ruling follows years of legal battles to advance the case.
"I am really delighted with the outcome of the case," he told Reuters in an interview. "It is a strong recognition that you cannot simply have two behemoths run the app economy and dictate to everybody else, ‘this is how it is going to be, and there's nothing you can do about it."
Makanjuola claims in the lawsuit that Apple and Google charge excessive fees for in-app purchases, which the complaint says are typically 30% of the purchase price, as well as restrictions on using payment systems other than their own.
According to the complaint, the companies are acting as gatekeepers that impose "onerous and unlawful terms and conditions on developers, which in turn are passed on to consumers in the form of inflated prices."
Apple did not immediately respond to a request for comment. Google declined to comment.
The lawsuit is one of several legal challenges that Apple is facing. The company is also battling Fortnite creator Epic Games over control of the App Store, and the European Union is reviewing Apple's App Store policies for possible breaches of competition laws.
For Makanjuola, who represents himself in the case, Saturday's ruling is a significant victory in pursuing his claims.
"I think there is a light at the end of the tunnel. And I am very eager to see what the district court does with this," he said.
