The UK’s competition watchdog has opened a new front in the global regulatory offensive against Big Tech, with Microsoft’s deeply entrenched business software ecosystem now squarely in its sights. On May 14, 2026, the Competition and Markets Authority (CMA) formally launched a Strategic Market Status (SMS) investigation into the company’s productivity, cloud, and enterprise software stack, unleashing a flood of third-party submissions that paint a picture of a market stifled by bundling, self-preferencing, and opaque licensing.

Industry rivals and business customers did not hold back. Within days of the launch, the CMA published a trove of responses from independent software vendors, cloud providers, and enterprise IT leaders, nearly all of whom described Microsoft as a gatekeeper that uses its Windows and Office strongholds to lock out competitors and drive customers toward its own adjacent services. The submissions, some heavily redacted, argue that Microsoft’s practices around Teams, Azure, and productivity suites have created an uneven playing field that the SMS probe must dismantle.

The investigation marks a pivotal moment for the UK’s new digital markets regime, which came into force in 2025. Under the Digital Markets, Competition and Consumers Act, the CMA can designate firms with “Strategic Market Status” in a particular digital activity and impose tailored, binding codes of conduct. For Microsoft, the focus is on its “business software stack” — a catch-all term covering operating systems (Windows), cloud infrastructure (Azure), productivity applications (Microsoft 365), collaboration tools (Teams), and related enterprise services. The CMA’s decision to probe this entire stack, rather than isolated products, signals a belief that the sum is more anti-competitive than its parts.

What Is Strategic Market Status?

Strategic Market Status is not a sanction in itself but a precursor to intervention. Once a firm is designated in respect to a digital activity, the CMA can require it to change behaviors that exploit its market power. The threshold is high: the business must have “substantial and entrenched market power” and a position of “strategic significance.” In Microsoft’s case, the CMA’s opening notice points to its absolute dominance in desktop operating systems and office productivity software, which it argues gives the company an “unassailable gateway” to business customers.

The designation covers the entire lifecycle of enterprise IT, from the moment a company purchases Windows licenses for its workforce to how it manages data, communications, and cloud workloads. The CMA suspects that Microsoft leverages must-have products like Windows and Office 365 to drive adoption of Teams, Azure, and even edge products like Power Platform. Rivals claim this bundling has crushed individual competitors — Slack, Zoom, Salesforce, and Snowflake are frequently cited in the submissions — and has forced businesses into a single-vendor dependency they cannot escape without prohibitive switching costs.

The Third-Party Submissions: A Chorus of Frustration

The published submissions, while stripped of sensitive commercial data, reveal a cauldron of long-simmering resentment. One UK-based independent software vendor (ISV) specializing in customer relationship management wrote that Microsoft’s practice of integrating its own Dynamics 365 deeply into Outlook and Windows “makes it impossible for us to compete on functionality — we’re constantly battling integration gaps that Microsoft artificially maintains.” Another, a cloud services provider, detailed how Azure’s licensing rules make it cost-prohibitive to run Windows Server workloads on rival clouds, effectively locking customers into the Microsoft ecosystem.

A particularly scathing submission came from a coalition of European cloud providers, which accused Microsoft of “taxing” businesses that choose alternatives. They pointed to Azure Hybrid Benefit changes in 2023 that allowed customers to use existing Windows Server licenses on any cloud — but only if they also purchased Software Assurance. That “double-dip,” the coalition argues, penalizes multi-cloud strategies. “The net effect is that customers pay more for the same Microsoft software when they deploy it on AWS or Google Cloud than they do on Azure,” the submission states. “That is not a level playing field.”

Enterprise IT leaders echoed these frustrations in their own responses. A FTSE 100 CTO described managing Microsoft licensing as a “nightmare that improves only when you commit to Azure and Office 365 E5.” Several submissions included internal cost analyses showing that moving away from Microsoft would require years of architectural overhaul — and that even then, core productivity would suffer because “no substitute has the same universal file compatibility.” The CMA has since indicated it will conduct its own market studies to quantify switching costs and lock-in effects.

Under the Microscope: Bundling, Self-Preferencing, and Licensing

The CMA’s investigation is built around three pillars of potential harm:

  • Bundling and tying: The integration of Teams with Office 365 and Windows, the linking of OneDrive with File Explorer, and the push toward Azure from Windows Server are all under scrutiny. Submissions paint a picture of a company that adds features and services to its dominant platforms and then defaults them to “on,” leaving rivals with no realistic chance to compete for the user’s attention.

  • Self-preferencing: Even when Microsoft allows third-party integrations, rivals say the company gives its own offerings unfair advantages — from deeper API access to preferential placement in the user interface. Slack’s parent company, now part of a larger enterprise software group, argued in its submission that Teams’ “seamless” calendar and email hooks were only achievable because Microsoft controls the underlying infrastructure, a privilege denied to competing collaboration tools.

  • Opaque licensing and audit tactics: Several submissions claim Microsoft’s enterprise agreements, with their complex rules on virtual desktop access and user subscription licensing, make it nearly impossible for companies to understand their actual costs and rights. Worse, audits are “used as a weapon” to push customers toward more comprehensive, and more expensive, agreements, a practice that one law firm submission called “de facto coercive upselling.”

Microsoft’s Defense: “We Compete on Merit”

Microsoft has pushed back vigorously. In a statement issued hours after the investigation was launched, the company said it looks forward to “working constructively with the CMA” but insisted that its business software stack “delivers tremendous value and choice to customers.” A spokesperson highlighted Microsoft’s investments in open APIs, its support for Linux on Azure, and the availability of its software on third-party marketplaces as evidence of a “commitment to interoperability.”

On the bundling of Teams, Microsoft pointed to its 2023 unbundling in the European Economic Area, a move it now says has been adopted globally. “Customers are free to choose any collaboration tool they want,” the statement read, “and many do.” The company also emphasized that its “Azure Hybrid Benefit” and “Azure Dedicated Host” programs give customers flexibility that rivals do not. “We are not locking customers in,” the spokesperson argued. “We are giving them reasons to stay with better service and lower total cost.”

But those arguments cut little ice with competitors. “Unbundling Teams in 2023 was not a sincere concession,” one submission retorted. “It took the EU threatening action, and even then, Microsoft removed Teams from Office suites only to re-bundle it into Windows 11’s taskbar and Edge’s sidebar. The packaging changed, but the gatekeeping didn’t.”

The Windows Anchor and the Enterprise Trap

Windows remains the bedrock of Microsoft’s enterprise power, and the CMA is acutely aware of it. For decades, businesses have built their IT around Windows because it is the de facto standard for desktop computing. That gave Microsoft a natural advantage when it launched Office, then Office 365, then Azure. Today, a typical mid-size company runs Windows on employee devices, uses Azure Active Directory (now Entra ID) for identity, stores files on OneDrive, collaborates in Teams, and manages devices via Intune. Extracting any single component is technically painful and economically irrational.

The submissions hammer this point. An IT services firm that helps businesses migrate to the cloud wrote that “the technical debt of leaving Microsoft is enormous, and Microsoft knows it.” It described clients who tried to move to Google Workspace but found that Excel macros, PowerPoint templates, and line-of-business applications that rely on Windows APIs made the transition untenable. “Microsoft doesn’t need to lock the door,” the firm’s director wrote. “It just needs to make the key too expensive.”

Global Context: A World of Regulators Circling

The UK is not acting alone. The EU’s Digital Markets Act has already forced changes in Microsoft’s behavior, and the U.S. Federal Trade Commission is reportedly preparing its own suit over cloud practices. The CMA’s investigation, however, may prove uniquely consequential because of the broad scope of its SMS regime. Unlike the DMA, which applies only to pre-defined core platform services, the UK system allows the regulator to tailor remedies to the specific facts of each market. That could lead to more surgical, and more potent, interventions.

Legal experts note that the CMA has a reputation for being less deferential to tech giants than its European counterparts. Its 2022 decision to block the Meta/Giphy deal, later upheld, showed a willingness to dig into ecosystem effects. “The CMA is not afraid to write bold rules,” said one competition lawyer who has followed the SMS regime. “If they designate Microsoft, we could see prohibitions on tying Teams to Windows, rules requiring equal access to APIs, and even a forced separation of the cloud and software licensing businesses.”

What Could Happen Next?

The investigation is still in its early stages. The CMA’s timetable suggests a provisional designation decision by Q4 2026, with a final SMS designation — and draft conduct requirements — by mid-2027. If designated, Microsoft would be forced to comply with a set of binding obligations, which could include:

  • Requiring fair, reasonable, and non-discriminatory (FRAND) licensing terms for competitors
  • Prohibiting practices that tie Windows to other services
  • Mandating data portability tools that give customers a genuine path out
  • Imposing a firewall between development teams for competing services

Failure to comply can trigger fines of up to 10% of global annual turnover, a figure that for Microsoft would run into the tens of billions of dollars. That alone concentrates the corporate mind.

For enterprise IT buyers, the investigation could bring overdue relief. “We’ve been begging for transparent, flexible licensing for years,” said the CTO of a UK-based manufacturing firm in his submission. “Maybe now someone is finally listening.” Others worry that regulatory intervention could backfire, complicating licenses further and slowing innovation. But the weight of the submissions suggests that the pain of the status quo is broadly felt.

The Road Ahead for Microsoft and Its Customers

Microsoft’s business software machine generates over $200 billion in annual revenue, and its operating margins in productivity and cloud are the envy of the industry. Any regulatory action that forces it to unbundle, open up, or re-structure could have ripple effects across the global technology landscape. For Windows enthusiasts, the most tangible changes might come in the form of a cleaner operating system, one where third-party collaboration tools are not disadvantaged by default integration choices. But there is also a risk that Microsoft, in complying, makes Windows less seamless — a trade-off that will test the loyalty of its massive user base.

The next 18 months will be critical. The CMA is now wading through thousands of pages of submissions and will soon start holding hearings with both Microsoft and its detractors. Whatever emerges, it is already clear that the era of unchecked bundling in enterprise software is drawing to a close. Microsoft’s playbook, perfected over three decades, is being rewritten — not by competitors, but by the regulators who believe the market has been starved of choice for too long.