Music streaming giant Spotify complained to the EU back in March about the “Apple tax” and a possible monopoly situation. Earlier this month, Europe’s antitrust chief said that a response from the Cupertino-based company is needed before a decision can be taken on the matter.

Apple has now complied and told European antitrust regulators that it collects a 15% fee from about 680,000 of its 100 million premium customers, Reuters reports. Apple’s business model is to charge a 30% fee for in-app purchases made through the App Store in the first year, after which it drops to 15%.

The iPhone-maker also made it clear that Spotify used its App Store billing system between 2014 and 2016. During that time 680,000 users subscribed to Spotify’s premium service through the App Store, and, since it was more than one year ago, Apple was only collecting 15% and only for those 680,000 users.

Spotify didn’t comment on the numbers made public by Apple, but also complained that Apple wouldn’t allow its service to operate on the company’s smart speaker, the HomePod.

Spotify and Apple are direct competitors (through Apple Music) in the music streaming service industry.