UK Opens Antitrust Probe Into Microsoft’s Business Software Ecosystem
The UK’s CMA has launched a formal antitrust investigation into Microsoft’s business software ecosystem.
Why it matters: The probe signals intensified regulatory scrutiny on dominant software providers, impacting legal tech platforms and law firms reliant on Microsoft. The outcome could influence vendor selection and the compliance landscape for enterprise customers in the UK.
- The CMA began its Strategic Market Status investigation into Microsoft on May 14, 2026.
- The probe examines concerns around product bundling, interoperability, and default settings in Microsoft’s ecosystem.
- Public and challenger tech firms can submit feedback to the CMA until June 4, 2026.
- Findings could lead to a designation of Microsoft as having Strategic Market Status by February 2027.
The Competition and Markets Authority (CMA) announced a Strategic Market Status (SMS) investigation into Microsoft’s business software ecosystem on May 14, 2026. The regulator will assess the competitive impact of Microsoft’s business software suite, including how practices like product bundling, interoperability restrictions, and default settings may affect UK businesses and public sector entities.
- The CMA invites responses from tech challengers, customers, and rivals with a deadline for submission set at June 4, 2026.
- The investigation is expected to conclude by February 2027, after which the regulator will consult publicly before making a final determination on SMS designation.
This investigation builds on the CMA's 2025 cloud services market review, where both Amazon and Microsoft were found to hold significant market shares (each controlling 30%-40% of the sector) and where concerns about data egress fees and limited interoperability were highlighted as barriers to competition.
CMA Chief Executive Sarah Cardell emphasized, "Business software is a cornerstone of how the UK economy functions...Hundreds of thousands of customers in the UK rely on Microsoft’s systems, which is why it’s so important to ensure these services are delivering good outcomes."
Microsoft has stated it is "committed to working quickly and constructively with the CMA to facilitate its review of the business software market." (full statement)
For law firms and corporate legal departments—many of whom are deeply embedded in the Microsoft environment—this scrutiny could reshape vendor relationships, compliance requirements, and technology strategy in coming years.
By the numbers:
- 30–40% — Share of UK cloud infrastructure market held by Microsoft and Amazon, per the CMA’s 2025 review.
- Feb 2027 — Expected conclusion date of the CMA’s investigation.
- June 4, 2026 — Deadline for public feedback to the CMA.
What's next: The CMA’s investigation is expected to conclude by February 2027, with a public consultation before final SMS designation.