Apple announced Wednesday it would permit users in the U.S. to make purchases outside its App Store, provided major app developers pay a 27% commission.

The changes come after the tech group faced a legal challenge from Fortnite maker Epic Games as part of a battle over fees spanning back to 2010. 

While the judge sided with Apple on most counts, they ruled the company was in violation of a competition law by failing to tell users about ways to make purchases outside the App Store.

Under the change, developers can now redirect customers to bypass the App Store payment system by using things like external links.

Apple is now chasing Epic Games for $73.5 million to cover losses and legal costs following its win, according to a Tuesday filing.

While the biggest app developers, including Spotify, will face a 27% fee on purchases made away from the store, sales from smaller developers and the auto-renewal of subscriptions will face a 12% charge. 

In a vitriolic statement, Spotify argued the latest charge “flies in the face” of attempts by the U.S. to introduce more competition to the tech sector.

A representative for Apple didn’t immediately respond to Fortune’s request for comment.

Apple’s fees back in spotlight

Major developers selling digital goods and services on Apple’s App Store pay the group a 30% commission fee on apps and in-app purchases, including subscriptions. 

However, small developers pay about a 15% commission, while 85% of developers pay no fees at all.

“All App Store developers—including those who place buttons or links with calls to action in their apps — benefit from Apple’s proprietary technology and tools protected by intellectual property, and access to its user base,” Apple said as it disclosed the changes in a court filing.

The new fee for external purchases, though, has sparked Spotify’s latest missive against Apple, extending a long-running tussle with the group over what the streaming platform views as anti-competitive charges.

“Once again, Apple has demonstrated that they will stop at nothing to protect the profits they exact on the backs of developers and consumers under their app store monopoly,” a representative for the group told Fortune in a statement.

“Their latest move in the U.S.—imposing a 27% fee for transactions made outside of an app on a developer’s website—is outrageous and flies in the face of the court’s efforts to enable greater competition and user choice.”

Spotify called for the U.K. government to step in to prevent similar fees passing in the country. The Digital Markets, Competition and Consumer Bill, which would impose tough new rules on major tech players, is currently passing through the country’s houses of parliament. 

Spotify’s fight with Apple 

Spotify and the group’s CEO Daniel Ek have repeatadly lamented Apple’s charges, which fall on any subscriptions to the streaming platform made through the app store.

The group views the charges as giving Apple a leg-up with its own music streaming offering, Apple Music, which is less popular than Spotify.

In an October op-ed for the Daily Mail, Ek said the charge, which Google’s app store also levies, hobbled competition and allowed the groups monopolistic control in the tech sector.  

Ek argued that he wouldn’t have been to create his $40 billion streaming platform if he had come up with the idea today, owing to those fees. 

“Today, Apple and Google are not just players, they are the rule-makers and gatekeepers of the mobile internet, controlling how more than 5 billion global consumers interact online,” Ek wrote.

The European Commission launched an antitrust investigation into Apple in 2020 after Spotify made complaints about the 30% fee it pays the company.

In February, the EU narrowed its this investigation to exclude Spotify’s request to remove the charge from the sale of digital goods and services.

“The App Store has helped Spotify become the top music streaming service across Europe, and we hope the European Commission will end its pursuit of a complaint that has no merit,” a representative for Apple previously told Fortune in a statement.