Meta Platforms, Microsoft, X and Match Group backed Epic Games in the game developer’s row against Apple over alleged anticompetitive App Store practices, arguing the iPhone-maker violated a court order in multiple ways.

In a filing, the companies recommended the US Supreme Court reject Apple’s revisions on its App Store purchase mechanism, claiming the changes contain anti-steering practices and impose new barriers for developers.

Apple’s revisions enable third-party developers to include a link directing customers to out-of-app payment systems.

To do this, the companies explained developers have to obtain permission through a “StoreKit External Purchase Link Entitlement”, a process the iPhone-maker has put in place which involves “dozens of requirements and limitations”.

This results in restrictions on their “ability to link to an external payment mechanism that dictate every aspect of developers’ communications with their users, stifling transparency and price competition, and denying meaningful consumer choice”.

In the filing, they also bemoaned “inflated commission” developers have to pay after a user clicks on an external payment link, and a requirement forcing developers to use their own webpage rather than a third-party payment platform. These moves are designed to prevent new payment channels and burden developers with operational costs, they added.

“Apple’s restrictions will have real-world adverse impacts on both consumers and app developers that extend beyond the Epic Games store and beyond mobile gaming generally,” the filing read.

Apple has until 3 April to respond. The company had recently allowed Epic Games’ Fortnite gaming title back on its App Store after removing it in 2020.