The European Commission on June 25, 2026, opened a formal investigation into whether Amazon Web Services (AWS) and Microsoft Azure should be designated as gatekeepers under the Digital Markets Act (DMA), marking the first time the bloc’s toughest antitrust tool has been aimed at the cloud infrastructure market. The probe, which could drag the two giants into a new era of mandated interoperability and data portability, arrives as regulators grow increasingly wary of how dominance in cloud computing translates into an unassailable edge in artificial intelligence.

“Today, we are initiating market investigations into two providers of cloud infrastructure services that appear to hold an entrenched and durable position in the EU,” a Commission spokesperson said in a statement. “The designation as gatekeepers would come with clear obligations to ensure fairness and contestability.” The Commission added that AWS and Azure likely meet the DMA’s quantitative thresholds—annual EU turnover of at least €7.5 billion, market capitalization of €75 billion, and a platform serving more than 45 million monthly active end users or 10,000 yearly business users in the EU—and that qualitative factors like market concentration justify a full probe.

The announcement sent ripples through Brussels and beyond, with shares of both companies dipping slightly in after-hours trading. For Microsoft, the timing is particularly awkward: the company is simultaneously navigating separate EU scrutiny of its AI partnerships and the bundling of Teams with Office. AWS, meanwhile, faces growing pressure from European sovereign cloud initiatives that threaten to chip away at its overwhelming market share.

The DMA Gatekeeper Framework

The DMA, in force since November 2022, applies to core platform services that act as bottlenecks between businesses and consumers. So far, the Commission has designated seven gatekeepers covering twenty-four core platform services, including Google Search, Apple’s iOS, Meta’s Facebook, and Amazon’s online marketplace. Cloud computing was conspicuously absent from that first wave—a gap critics argued left a glaring loophole, given how essential cloud infrastructure has become for everything from business applications to AI training.

Once a company is designated as a gatekeeper for a specific core platform service, it must comply with a laundry list of obligations within six months. Chief among them:

  • Interoperability: Gatekeepers must allow third-party services to interoperate with their own, for example, enabling enterprise users to mix cloud providers without artificial barriers.
  • Data portability: Customers must be able to easily transfer their data off the platform, and gatekeepers cannot lock in data through restrictive contracts or technical measures.
  • Anti-self-preferencing: A gatekeeper cannot rank its own services higher than rivals in search results or recommendations—a rule that could force cloud providers to stop steering customers toward their own AI models or SaaS products.
  • Switching and uninstallability: Gatekeepers must allow business users—in this case, companies that build on top of cloud infrastructure—to switch providers without penalty and must not make it technically difficult for end users to leave.
  • Transparent pricing and T&Cs: Clear, fair, and non-discriminatory terms must be offered to all business partners.

Failure to comply can trigger fines of up to 10% of global annual turnover, rising to 20% for repeat offenses. The Commission can also impose structural remedies, though breaking up companies remains a weapon of last resort.

Why AWS and Azure?

The Commission’s preliminary assessment points to a cloud market that is overwhelmingly dominated by two players. According to Synergy Research Group, AWS commanded 32% of global cloud infrastructure spending in Q1 2026, with Microsoft Azure at 23%. In the EU, that combined share likely exceeds 60%, with Google Cloud a distant third at around 11%. But raw market share isn’t the only factor. The Commission zeroes in on the “layered” nature of the cloud stack—IaaS, PaaS, SaaS—and how incumbents can leverage footings in one layer to dominate another.

Both AWS and Microsoft have been accused of licensing practices that make it more expensive to run workloads on rival clouds. For years, Microsoft faced loud complaints from European competitors like OVHcloud, Nextcloud, and Deutsche Telekom-backed Nextcloud, who argued that Windows Server licenses bundled with Azure skewed the market. In 2023, Microsoft tweaked its licensing to placate critics, but the damage was done; many midsize enterprises felt locked into Azure’s ecosystem.

AWS’s alleged sin is different: its sprawling portfolio of proprietary services—ranging from NoSQL databases to machine learning tools—creates a gravity well that pulls customers deeply into the AWS orbit. Once a company adopts Amazon’s Aurora database or SageMaker AI platform, migrating out becomes a multi-year, multi-million-euro project. The DMA’s data portability and interoperability mandates could force Amazon to expose APIs that decouple those services.

A New Front in the Cloud Wars

If designated, AWS and Azure would be compelled to dismantle some of the very walls that protect their recurring revenue streams. Egress fees—charges for moving data out of a cloud—have long been a friction point. While both companies offer free tiers of egress for switching under voluntary programs, the DMA would make free switching a legal requirement, not a marketing promise. Analysts estimate that egress fees alone account for a significant portion of cloud margin, and their elimination would reshape pricing models.

Licensing would also come under the microscope. The Commission is likely to probe whether Microsoft’s “Azure Hybrid Benefit” or “bring your own license” policies effectively penalize customers who choose alternative clouds. Under the DMA, Microsoft could be forced to sell licenses for Windows Server, SQL Server, and other enterprise products on fair terms regardless of where the software is hosted. That would be a seismic shift, potentially eroding Azure’s unique selling proposition that it is the best and cheapest place to run Windows workloads.

For AI, the stakes are even higher. The Commission’s announcement specifically flagged “the entrenchment of cloud providers in the AI value chain.” Both AWS and Azure are rapidly weaving AI services—like Amazon Bedrock and Azure OpenAI Service—into their platforms. Those services often tie back to the underlying cloud, creating a double lock-in: proprietary AI models and proprietary infrastructure. The DMA could force providers to allow AI models to be run on any cloud, and to ensure that third-party AI services get equal treatment on their platform. That principle, if enforced, would echo the interoperability mandate that forced WhatsApp to open up to other messaging apps.

What the Probe Means for Microsoft

For Windows enthusiasts, the probe raises immediate questions about the integration between Azure and the Windows desktop ecosystem. Microsoft has long used its dominance in the operating system and productivity suite to funnel businesses toward Azure. For instance, Windows 11 Pro for Workstations and Windows Server editions heavily promote Azure Active Directory (now Microsoft Entra ID) and Azure Backup, while the Microsoft 365 admin center nudges IT admins toward Azure Virtual Desktop. If the DMA labels Azure a core platform service, those nudges could be construed as illegal self-preferencing.

“This is more than just about cloud infrastructure,” said tech antitrust scholar Cristina Caffarra in a commentary piece. “It’s about the full Microsoft stack—from Windows to Office to Azure to Copilot. The DMA could force Microsoft to open the plumbing between all these layers, undoing decades of integration strategy.” Indeed, the forthcoming Windows 12, expected to integrate Copilot at the kernel level, might face extra scrutiny if any part of that integration steers users toward Azure-hosted AI.

On the other hand, Microsoft’s recent embrace of open standards and its partnership with rival cloud providers through the Azure Native ISV Services program may give it a stronger defense than Amazon. The Commission will likely examine whether such initiatives are genuine or merely cosmetic.

Industry Reactions: Applause and Alarm

The cloud industry fractured immediately along predictable lines. German cloud provider Ionos praised the probe as “long overdue,” with CEO Achim Weiss stating, “European businesses have suffered for years from unfair bundled pricing and locked-in data. The DMA finally gives us a framework to level the playing field.” French provider Scaleway echoed the sentiment, calling for rapid designation and aggressive enforcement.

AWS and Microsoft issued brief, carefully worded statements. Amazon said it would “cooperate fully with the Commission,” while expressing confidence that its services “operate in a highly competitive market that benefits millions of European customers.” Microsoft’s statement was more conciliatory: “We are committed to providing cloud solutions that meet the rigorous standards of European regulators. We look forward to demonstrating how Azure fosters innovation and choice in the EU.” Both companies are expected to mount a vigorous defense, arguing that the cloud market is dynamic, with new entrants like Oracle Cloud and Chinese providers gaining ground.

European consumer group BEUC welcomed the investigation but warned that enforcement must be swift. “Designating gatekeepers is only the first step,” said senior digital policy officer Maryant Fernández. “The real test is whether the Commission orders concrete, measurable remedies before the next generation of AI monopolies solidifies.”

Others pointed to the irony that the EU’s own push for digital sovereignty—through initiatives like GAIA-X—has struggled to gain traction precisely because of the dominance that the DMA now targets. “Regulation is a sign that the market has failed to self-correct,” said John Dinsdale, chief analyst at Synergy Research. “But regulation also carries a risk of unintended consequences, especially in a sector as complex as cloud.”

Next Steps and the Path to Enforcement

The Commission’s investigation will run for a maximum of six months from the June 25 announcement. During that period, AWS and Microsoft will have the opportunity to submit evidence, rebut allegations, and propose commitments. At the end, the Commission issues a decision designating the platforms as gatekeepers or closing the investigation. If designated, the companies have another six months to comply with the DMA’s obligations. In practice, that means enforcement could begin as early as mid-2027.

Fines for non-compliance would be calculated on global annual revenue—a financially meaningful threat for two companies that together generated over $200 billion in cloud revenue in 2025. However, historical precedent suggests that both sides might negotiate a compliance package that avoids heavy penalties. Google, for example, worked with the Commission for months to shape its DMA compliance on Search and Maps, resulting in a relatively smooth rollout.

European Commission Executive Vice President for Competition and Digital Policy, Teresa Ribera, will oversee the investigation. She has already hinted at a comprehensive approach. “Our focus is not just on the current cloud market, but on how these infrastructures will underpin the AI-driven economy of 2030,” Ribera said in a recent op-ed. “We must ensure that the gatekeepers of today do not become the bottleneck for the innovations of tomorrow.”

A Ripple Effect Across the Atlantic and Beyond

The EU probe is likely to embolden regulators elsewhere. The UK’s Competition and Markets Authority, which recently flexed its muscles in AI foundation models, has already signaled interest in cloud switching costs. U.S. lawmakers, though currently gridlocked on tech antitrust, may cite the EU action as evidence that American companies are being unfairly targeted by foreign regulators—or conversely, as a template for much-needed reform. The pragmatic outcome is that both AWS and Azure will face a growing patchwork of rules, potentially prompting them to adopt the EU’s DMA standards globally to avoid fragmentation.

For Windows users and IT administrators, the probe carries both promises and pitfalls. On the one hand, genuine interoperability would free businesses from vendor lock-in and could spark a new wave of multi-cloud innovation. On the other, hastily crafted compliance measures might break seamless integrations that millions rely on daily, from Windows authentication to Azure-based AI features in Microsoft 365. The upcoming months will be a delicate dance between regulators and platform architects, with the EU’s 450 million citizens watching closely.

As the Commission’s investigation gets under way, one thing is clear: the era of laissez-faire cloud is ending. The biggest question is not whether AWS and Azure will be designated gatekeepers—that now seems all but certain—but how profoundly they will be forced to open their doors, and whether that openness arrives in time to shape a truly competitive AI future.