The CMA Comes Knocking on Redmond's Door
The UK's Competition and Markets Authority is digging into Microsoft's business software ecosystem, and the complaints pouring in paint a picture of a company that's gotten awfully comfortable with its own dominance. The investigation, which kicked off back in May, is looking at everything from product bundling and default settings to how Microsoft handles AI integration — specifically Copilot — and its licensing practices. The regulator's stated goal is straightforward: make sure UK organizations can actually mix and match software from a broad range of competing suppliers instead of being herded into one walled garden.
What's striking about this round isn't just the scope of the inquiry, but who's talking. We're not looking at a narrow circle of enterprise IT managers grumbling about renewal prices. Google has filed a formal submission. Mozilla is complaining about Windows 11's habit of silently switching you to Edge during upgrades. A parish council in Yorkshire is upset about an unexpected £1,100-a-year bill. This is what happens when a company gets big enough that even people who never thought about antitrust regulation start feeling the pinch.
The CMA has published all these submissions, which means we can actually see what each complainant is arguing. And honestly? The pattern's pretty clear.
Google Calls Microsoft a Gatekeeper
Google's submission is probably the one that matters most from a regulatory standpoint. The search giant alleges that Microsoft is "effectively a gatekeeper" and uses its entrenched market position to steer captive users toward its own cloud and AI solutions. That's a loaded word — gatekeeper — because it implies Microsoft isn't just winning fairly in the marketplace but actively controlling access points that competitors need to reach users.
The Browser Choice Alliance backed this up with a more specific complaint: Microsoft leverages its dominant Windows operating system and the M365 productivity suite to frustrate users' choice of browsers. Mozilla pointed to Windows 11's tendency to default to Edge, particularly during the upgrade flow — a practice that's been controversial for years and feels even more aggressive now that Edge is deeply integrated with Copilot.
Vivaldi, the privacy-focused browser, also weighed in. And then there's Collabora, which made a technically nuanced but practically important point: the CMA should explicitly include both APIs and document format standards — specifically Office Open XML, or OOXML — within the scope of what it considers the Productivity Software Suite. Their argument is that Microsoft's own applications treat OOXML as a de facto standard while embedding undocumented complexities that create significant technical barriers for third-party suites trying to interoperate. In other words, the file format looks open on the surface but works like a trap for anyone trying to build something compatible.
Open Web Advocacy and the Open Cloud Coalition — which The Register previously described as a Google lobby group, though that's a detail Microsoft would happily gloss over — also submitted comments. Element, the open messaging platform, joined the fray too. The coalition of complainants is broadening by the day.
A Parish Council's £1,100 Problem
Here's where the story gets genuinely human. Killinghall Parish Council — yes, that's a real place, in North Yorkshire — has complained to the CMA about an unplanned annual cost of £1,100 for additional Microsoft services required to use Teams effectively. Their submission states plainly: "We are concerned that Microsoft's refusal to integrate fully with third-party products creates unnecessary additional costs for Parish Councils."
Think about that for a moment. A tiny local government body with probably fewer than twenty staff members is now a formal party in an antitrust investigation against the world's most valuable company. They're not complaining about enterprise licensing deals or data center competition. They're complaining that Microsoft won't let their existing tools talk to Teams properly, and the only fix is buying more Microsoft products.
It's the kind of complaint that sounds almost absurd until you realize it's exactly the kind of lock-in behavior antitrust regulators are supposed to care about. If a parish council can't afford the workarounds, what's happening to mid-size businesses? And if a parish council is being squeezed this hard with Microsoft's full attention on them, what does that say about how the company treats smaller customers who can't push back?
The Register ran with this angle for good reason. It's the story that makes abstract regulatory concerns feel real.
Microsoft's Defense: We're Just Competing
Naturally, Microsoft pushed back hard. The company argued that it faces "substantial competitive constraints across all five digital activities" the CMA is examining. In productivity software, they pointed to Google Workspace and LibreOffice as vigorous competitors. Windows faces competition from macOS and Linux — and Linux, they noted, is a far more widely used server operating system than most people realize. Databases like PostgreSQL and MySQL compete with SQL Server, and Okta makes a "decent fist" of Identity and Access Management.
Microsoft also asserted that its commitment to openness and interoperability is "real, deep and growing" — a line that will sound about as reassuring to the complainants as you'd expect. And perhaps most interestingly, they claimed that "AI is making competition more intense, not less," essentially arguing that the very Copilot integration the CMA is investigating is actually a pro-competitive force.
That's a defensible position in theory. AI tools from multiple vendors can coexist, and Microsoft's argument is that the market is expanding faster than any single player can dominate it. But the complainants' counter-argument is equally clear: when your AI features are baked into the operating system and the productivity suite, they're not really competing on a level playing field. They're riding on top of an existing monopoly.
The tension between these two narratives — Microsoft saying the market is wide open, and everyone else saying it's rigged — is exactly what the CMA needs to untangle.
What Happens Next
The CMA's investigation has a few more months to run before we see any concrete outcomes. A proposed decision will be published for public consultation in October, and the final decision report — along with any Strategic Market Status designation notice — is expected in February 2027.
An SMS designation would be a big deal. It would allow the CMA to implement targeted interventions designed to support competition in Microsoft's favor areas, potentially forcing changes to bundling practices, default settings, and interoperability requirements. It's the kind of regulatory tool that hasn't been used aggressively against tech companies in the UK before, and its application here could set an important precedent.
The investigation also touches on Microsoft's cloud market practices — specifically allegations that the company uses software licensing to reduce cloud competition. An SMS designation could give the CMA authority to intervene on those concerns too, which would be significant given how much enterprise work has migrated to the cloud.
For now, the complainants have made their cases. Google, Mozilla, Vivaldi, Collabora, Element, Open Web Advocacy, the Open Cloud Coalition, and Killinghall Parish Council have all told the CMA where Microsoft's practices hurt them. The question is whether the regulator agrees, and what it's willing to do about it when it does.
For more insights on antitrust regulation and its impact on the tech industry, check out our article on Google's $4.7 Billion EU Fine Just Got Real: What the Shopping Case Actually Means. Additionally, explore how AI is reshaping economic policies in The New Architecture of Power: Corporate Autonomy and Global Economic Fragmentation.