The music-streaming service filed an European Union antitrust complaint on Monday night alleging that the maker has behaved unlawfully and abused its dominance in its App Store to favour the company's own rival Apple Music service.
Spotify has filed a complaint with European regulators over Apple's "unfair" app store practices, including the 30% commission that Apple pockets with every app purchase.
Ek believes that this app subscription "tax" is created to harm streaming services that compete with Apple's own services, such as Apple Music.
Meanwhile, other developers have also complained about Apple's constantly evolving App Store guidelines, which feels shifting goalposts that the company changes on a whim, often to suit its own interests while claiming to do so on behalf of its users.
Spotify founder Daniel Ek says Apple gets away with the gambit by circumventing existing rules by governing "self-interested" promotion app stores and marketplaces of the like. This made its service more expensive than Apple Music, and Spotify isn't happy about it.
Spotify also contends that Apple gives its own services an unfair advantage by allowing them to violate rules third-party services must abide by, like sending push notifications offering savings, or preventing the use of iOS APIs to recommend podcasts.
If Spotify was to ditch Apple's payment system, Ek continues, "Apple then applies a series of technical and experience-limiting restrictions on Spotify".
Ek points to the revenue share that Apple demands for services that charge customers via apps distributed through the App Store, unofficially known as the "Apple tax".
A dispute between Spotify and Apple has blown up into a public battle. The most prominent example is Apple's standoff with Amazon over Kindle e-books, which it wanted a cut of.
Spotify wants the same treatment as other App Store apps like Uber and Deliveroo, "who aren't subject to the Apple tax and don't have the same problems".
"Apple requires that Spotify and other digital services pay a 30 per cent tax on purchases made through Apple's payment system, including upgrading from our free to our premium service", Ek said. "After trying unsuccessfully to resolve the issues directly with Apple, we're now requesting that the European commission take action to ensure fair competition".
"We aren't seeking special treatment", Ek explains. He adds that all App Store users should have a choice of payment systems, and not be locked into using Apple's platform.
We've reached out to both companies and will update if we hear back. That's what competition on the merits is all about.