The Supreme Court is letting a group of consumers sue Apple for alleged monopolistic App Store policies.

In a 5-4 decision, the Supreme Court sided with four iPhone owners who contend the company has been inflating prices on the App Store —which is currently the only official place to download apps for iOS devices.

All App Store developers must also pay the company a 30 percent cut of apps sales. This requirement, and the lack of alternatives, can force consumers to overpay for their apps, according to the iPhone owners, who filed their class-action lawsuit against Apple in 2011.

In its defense, Apple has been arguing the company doesn't set the prices on the App Store; instead, the iPhone owners should only be able to sue the individual sellers on the platform. However, the Supreme Court disagreed, saying the company's legal arguments were neither "persuasive economically or legally."

"Apple's theory would provide a roadmap for monopolistic retailers to structure transactions with manufacturers or suppliers so as to evade antirust claims by consumers," Justice Brett Kavanaugh wrote in the opinion.

The Supreme Court's decision refrained from assessing the legal merits of the antitrust charges against Apple. But it does open the door for both consumers and app developers to sue the company over its alleged monopolistic iOS practices. Current antitrust laws allow the plaintiffs to recover three times the amount of damages.

The Supreme Court heard the case after a lower federal court ruled that the iPhone owners were "direct purchasers" from Apple when buying apps on the official App Store. In response, Apple wanted the Supreme Court to dismiss the lawsuit.

So far, the company hasn't commented on today's decision.