The European Union’s executive arm has started a process to provide Apple with guidance on how the iPhone maker can comply with rules to ensure its operating systems are functional with other technologies.

While the announcement is a step shy of being a formal investigation, the EU aims to compel Apple to re-engineer its services to allow rival companies to access the iPhone’s and iPad operating systems.

Apple Inc. has been warned by the European Union to open up its highly guarded iPhone and iPad operating systems to rival technologies, or eventually risk significant fines under its flagship digital antitrust rules.

The European Union has intensified its antitrust push against Apple, signaling the tech giant must open its closely guarded iPhone and iPad operating systems to rival technologies or risk significant fines.

The need to ensure Apple’s business is viable might turn out to be a very big deal. Europe has already fined Apple billions to protect the interests of European firm Spotify. It has clawed back (as Apple sees it) $14 billion in tax money. And yet, at least according to John Gruber, the EU contributes perhaps 7% of Apple’s global revenue.

The European Commission has begun to set out legal requirements for Apple to open up all of iOS and iPadOS to third parties, on top of allowing rival App Stores and payment systems.

Key Takeaways The European Union's enforcement arm said Thursday it's initiating a pair of "specification proceedings" into whether Apple is complying with its "interoperability obligations" under the Digital Markets Act.

The European Commission plans to come up with its own measures that Apple has to follow to ensure interoperability if it doesn't want to pay huge fines.