It is the latest exchange in an intensifying war of words between the companies that could become ugly.
In response to Apple claims that Spotify "wants all the benefits of a free app without being free", the music streaming service told Variety that Apple's behaviour is in violation of European law:
"Every monopolist will suggest they have done nothing wrong and will argue that they have the best interests of competitors and consumers at heart. In that way, Apple’s response to our complaint before the European Commission is not new and is entirely in line with our expectations," a Spotify spokesperson said.
"We filed our complaint because Apple’s actions hurt competition and consumers, and are in clear violation of the law. This is evident in Apple’s belief that Spotify’s users on iOS are Apple customers and not Spotify customers, which goes to the very heart of the issue with Apple. We respect the process the European Commission must now undertake to conduct its review."
How it all started
The main arguments put by Spotify and its boss Daniel Ek were that Apple charges a 30 per cent royalty fee on any Premium subscriptions made through its app on iOS, and also doesn't allow Spotify to advertise or incentivise free subscribers to become Premium members by pointing to an external site.
At the same time, Apple Music has, it claimed, posted promotions on its own app for paid subscriptions. Apple also doesn't have to pay itself royalties, of course.
Spotify called the 30 per cent fee an unfair "tax".
Apple's response was swift, claiming that the rules enforced on Spotify apply to every app on the App Store. It countered that Spotify wants all the benefits of being a free app on iOS, including the use of Apple APIs and ecosystem, but doesn't want to contribute financially in return:
"Apple connects Spotify to our users. We provide the platform by which users download and update their app. We share critical software development tools to support Spotify’s app building. And we built a secure payment system - no small undertaking - which allows users to have faith in in-app transactions. Spotify is asking to keep all those benefits while also retaining 100 percent of the revenue," it said in a statement.
Apple also claimed that Spotify failed to reveal that, while initial royalties on in-app subscriptions are 30 per cent, they drop to 15 per cent for every year after the first.
The last comment made by Apple was perhaps the most stinging. It referred to Spotify, Google, Amazon and Pandora's appeals against paying more royalties to artists for every track played. Apple Music is not part of that appeal process:
"We share Spotify’s love of music and their vision of sharing it with the world. Where we differ is how you achieve that goal. Underneath the rhetoric, Spotify’s aim is to make more money off others’ work. And it’s not just the App Store that they’re trying to squeeze - it’s also artists, musicians and songwriters.
"Just this week, Spotify sued music creators after a decision by the US Copyright Royalty Board required Spotify to increase its royalty payments. This isn’t just wrong, it represents a real, meaningful and damaging step backwards for the music industry."