The European Commission delivered a landmark decision on June 25, 2026, officially designating Amazon Web Services and Microsoft Azure as 'gatekeeper' platforms under the Digital Markets Act (DMA). The move, announced by Commissioner for Competition Margrethe Vestager, marks the first time cloud infrastructure services have been subjected to the bloc's tough antitrust rules, and it is poised to reshape the cloud computing landscape for businesses across the European Union.

Cloud computing has long operated under a paradigm of deep integration and proprietary ecosystems, with Windows-based businesses often feeling locked into Azure due to licensing advantages and hybrid tooling. The new classification upends that status quo, compelling the two dominant cloud providers to open their platforms, ensure data portability, and grant third-party services unfettered interoperability.

The DMA Gatekeeper Definition

The Digital Markets Act (Regulation (EU) 2022/1925) establishes criteria for designating 'gatekeepers'—large digital platforms that serve as critical conduits between business users and consumers. A company qualifies if it has an annual EU turnover of at least €7.5 billion in each of the last three years, provides a core platform service in at least three member states, and has more than 45 million monthly active end users and 10,000 yearly business users in the EU.

Until now, gatekeeper designations had targeted consumer-facing services: Alphabet (Google Search, Chrome, Android), Amazon (Marketplace, Advertising), Apple (iOS, App Store), ByteDance (TikTok), Meta (Facebook, Instagram), and Microsoft (Windows PC OS, LinkedIn). By extending the label to cloud infrastructure, the Commission signals that enterprise services are not exempt from antitrust scrutiny.

“After an in-depth investigation, we have concluded that both AWS and Azure play a central role in the digital economy,” Vestager said in a press briefing. “Their market power allows them to dictate terms to businesses, stifle competition, and lock customers into proprietary ecosystems. This must change.”

What the Designation Means for AWS and Azure

Under the DMA, gatekeepers must comply with a set of prescribed obligations and prohibitions within six months of designation. For AWS and Azure, the deadline is December 25, 2026. Failure to comply can incur fines of up to 10% of global annual turnover, and repeat offenses can reach 20%.

Key requirements that will force fundamental changes to the cloud platforms include:

  • Interoperability: Gatekeepers must allow third-party providers to interoperate with their own services at the same levels of functionality and security. This means other cloud vendors, software vendors, and managed service providers must be given APIs and access to enable seamless integration. For Azure, which tightly couples with Windows Server, Active Directory, and Visual Studio, this could upend its traditional integration advantage.
  • Data Portability: Business users must be able to easily transfer their data and application workloads to another cloud provider. Both AWS and Azure must provide tools for continuous, real-time data export, without fees or technical barriers. This direct challenge to vendor lock-in threatens the massive data gravity that keeps enterprises anchored.
  • No Self-Preferencing: The gatekeepers cannot rank their own products or services more favorably than those of competitors. For example, on a cloud marketplace, they cannot promote their own IaaS or PaaS offerings over a third-party's competing solution.
  • Fair Licensing: Any licensing terms tied to the cloud platform must be fair, reasonable, and non-discriminatory. This takes aim at Microsoft's contentious licensing practices, wherein running Windows Server or SQL Server workloads on non-Azure clouds often incurs higher costs or compatibility restrictions.
  • Transparency: Gatekeepers must disclose pricing, terms, and conditions in a clear and accessible manner. They must also provide performance metrics and uptime reports that enable customers to benchmark services objectively.

Both companies have six months to present a compliance plan to the Commission. Early signals suggest they will push back on specific technical and commercial details. “We are reviewing the Commission's decision and remain committed to providing a secure and innovative cloud platform,” a Microsoft spokesperson said. “We will work constructively with regulators to ensure compliance while minimizing disruption to our customers.” AWS offered a similar tone: “We believe our services already offer customers unparalleled choice and flexibility. We will engage with the Commission to clarify the scope of these new obligations.”

Consequences for Windows-Centric Businesses

For the large swath of enterprises that run Windows workloads, the DMA designation could be the most consequential regulatory shift since the cloud's inception. These “Windows shops” have traditionally favored Azure because of native integration with Microsoft's ecosystem: Active Directory synchronization, joint support for hybrid architectures, SQL Server performance optimizations, and the Azure Hybrid Benefit that reduces licensing costs for existing Microsoft software.

Under the new rules, Microsoft will have to extend those benefits in a non-discriminatory fashion. That could mean:

  • License Mobility Without Penalty: Customers may run Windows Server and SQL Server instances on AWS, Google Cloud, or on-premises hypervisors with the same terms and discounts they receive on Azure. The current practice of charging a premium for “license mobility” could be outlawed.
  • Interoperable Management Tools: Third-party tools must have the same access as Microsoft's own System Center, Azure Arc, and Windows Admin Center. A DevOps team using a competing monitoring platform would be able to manage Azure resources just as deeply as through Azure Portal.
  • Forced Decoupling of Services: Services like Azure Backup, Azure Site Recovery, and Azure Migrate might need to be unbundled so that customers can use equivalent offerings from competitors without loss of functionality. Today, using a third-party backup solution often means forgoing deep integration with Azure's infrastructure.
  • True Multi-Cloud Portability: Real-time data portability tools would allow a business to replicate an entire Azure VM set to AWS—or vice versa—with a few clicks. This could spur a wave of multi-cloud and hybrid architectures that reduce dependence on any single provider.

Bob Daniels, a cloud architect at a European financial services firm, expressed cautious optimism: “We've wanted to adopt a multi-cloud strategy for resilience, but the cost and complexity of running Windows workloads outside Azure have been prohibitive. If the DMA actually levels the playing field, we could see real competition on functionality and price, not just on lock-in.”

However, some IT leaders worry about short-term disruptions. “Whenever there's a regulatory compliance push, it means engineering resources diverted from feature development to paperwork and platform rework,” said Clara Mikkelsen, CTO of a Copenhagen-based SaaS firm. “In the short term, we might see some instability as both clouds rush to meet the deadline.”

Microsoft's history of bundling products under the “Better Together” mantra also faces a direct challenge. The company has long argued that deep integration delivers a superior experience. Now it must demonstrate that experience can be reproduced through open APIs and fair licensing—or risk fines that could reach tens of billions of euros.

AWS's Gatekeeper Hurdles

While much of the narrative centers on Microsoft and its Windows ecosystem, AWS faces its own set of compliance headaches. Amazon's cloud dominance (around 32% of the global market) was built on a vast catalog of proprietary services—from DynamoDB to Lambda—that often encourage lock-in through data egress fees and closed SDKs.

The DMA's prohibition of self-preferencing could force AWS to stop giving its own services prominent placement in the AWS console or marketplace. More significantly, the data portability mandate attacks the egress fee model directly; AWS will need to allow free data transfers out of its cloud, a move that could upend its business model. Customers have long complained that moving data out of AWS is prohibitively expensive, effectively locking them in.

Both companies now face the prospect of redesigning their platform architectures to accommodate interoperability. This could introduce new attack surfaces, prompting security teams to reassess risk postures. Enterprise architects will need to balance the newfound freedom with heightened security scrutiny.

Industry Reaction and Next Steps

Cloud industry analysts have called the designation a watershed moment. “For the first time, hyperscale cloud infrastructure is being regulated like a utility,” said Lars Vogelsang, principal analyst at Forrester. “This isn't about punishing AWS and Azure for success; it's about ensuring that the digital economy's plumbing is open and accessible. The next six months will determine whether this regulation creates genuine competition or just compliance theatre.”

European cloud providers, long vocal about unfair competition, welcomed the decision. “This is a victory for European businesses, which have been held hostage by restrictive practices,” said the chair of the Cloud Infrastructure Services Providers in Europe (CISPE). “We expect the compliance plans to deliver meaningful interoperability and license fairness.”

At a technical level, the commission will likely demand detailed API specifications and proof-of-concept demonstrations. AWS and Azure engineers will need to expose internal interfaces that have been closed for years. The process could mirror the interoperability workouts required of Microsoft after the 2004 antitrust ruling, which forced Windows to open protocols to competitors.

Windows shops should start preparing now. A proactive audit of cloud dependencies, licensing contracts, and data movement capabilities is essential. Enterprises should demand clarity from their cloud providers on new portability tools and negotiate for contract flexibility ahead of the compliance deadline. Multi-cloud planning, once a luxury, is becoming a strategic imperative.

The Broader Picture: A New Era of Cloud Regulation

The designation of AWS and Azure as DMA gatekeepers is part of a global trend. The UK's Competition and Markets Authority is examining cloud services, and the U.S. Federal Trade Commission has signaled interest in cloud competition under the FTC Act. But the EU, with its muscular regulatory approach, is once again setting the standard.

If successful, the DMA could unbundle the cloud, transforming it from a set of proprietary fortresses into a standardized utility. This would lower barriers for new entrants and give businesses the ability to assemble best-of-breed environments—perhaps using Azure for AI workloads, AWS for analytics, and Google Cloud for collaboration, all seamlessly managed through a single pane of glass.

Yet the path to implementation is fraught. AWS and Microsoft possess immense legal and lobbying resources, and they may seek to water down requirements through prolonged negotiations. The Commission has proven it will not hesitate to impose fines—as it did with Intel and Google—but the complexity of cloud technology could lead to endless disputes over what constitutes “real” interoperability.

For now, one thing is certain: the days of cloud walled gardens are numbered. Windows enterprises that have long felt tethered to Azure can start envisioning a more flexible future, though the transition will require careful strategy and robust governance.

June 25, 2026 is the day the cloud competition rulebook was rewritten, and the ripple effects will be felt in data centers and boardrooms across Europe for years to come.