Ms. Vestager said the commission has opened further investigations into Apple, including whether the company is killing rivals to Apple Pay, and has spoken to colleagues in the US, Australia and the Netherlands about the investigation.

“It is an area of ​​concern to a number of colleagues around the world,” Ms. Vestager said.

Spotify welcomed the European Commission’s decision. As of 2016, the Swedish company no longer allowed its customers to purchase a subscription through its iPhone and iPad apps to avoid paying Apple fees, but rather to drive visitors to the Spotify website.

“Ensuring the fair operation of the iOS platform is an urgent task with far-reaching implications,” said Horacio Gutierrez, head of global affairs and chief legal officer of Spotify, in a statement. The Commission’s announcement was “a crucial step in bringing Apple to account for its anti-competitive behavior and ensuring sensible choice for all consumers and a level playing field for app developers.”

Apple said its App Store policies didn’t hurt competition, but rather gave companies a platform to reach customers. The company said developers could find payment alternatives, noting that Spotify pays Apple low commissions because customers have to sign up through a website. Apple said Spotify has become the world’s largest music streaming service in part because of the App Store.

“They want all the benefits of the App Store but don’t think they have to pay anything for them,” Apple said in a statement. “The Commission’s argument on behalf of Spotify is the opposite of fair competition.”

The app store criticism is part of a wider debate about the power of the tech industry, where a small number of companies like Amazon, Apple, Facebook, and Alphabet, which own Google, have government-like powers to set guidelines for key parts of the digital economy. This agency determines how people find, communicate and shop for information and entertainment.