Stock Markets April 27, 2026 11:43 AM

Salesforce and Slack sue Microsoft in London over alleged Teams bundling

Lawsuit accuses Microsoft of tying Teams to Office to limit choice; comes amid separate UK cloud pricing litigation

By Ajmal Hussain MSFT
Salesforce and Slack sue Microsoft in London over alleged Teams bundling
MSFT

Salesforce and its workspace messaging app Slack have initiated legal action against Microsoft at the High Court in London, alleging anticompetitive conduct linked to the bundling of Teams with Microsoft Office. The case, filed April 23, follows a 2020 complaint to the European Commission and an agreement last year in which Microsoft agreed to offer reduced prices for Office without Teams. The suit arrives the same week a separate mass claim in the UK was certified, alleging overcharging by Microsoft for Windows Server use on rival cloud providers, which Microsoft disputes.

Key Points

  • Salesforce and Slack filed a lawsuit against Microsoft in London’s High Court on April 23 alleging anticompetitive tying and bundling of Teams with Office.
  • Slack previously complained to the European Commission in 2020; Microsoft agreed last year to offer reduced prices for Office products that exclude Teams.
  • The lawsuit coincides with a separate UK group action certified by the Competition Appeal Tribunal alleging Microsoft overcharged businesses for Windows Server use on rival cloud services; Microsoft disputes those allegations.

LONDON, April 27 - Salesforce and Slack have launched a lawsuit against Microsoft in London’s High Court, saying Microsoft engaged in anticompetitive tying and bundling related to its Teams application.

The legal action, filed on April 23 by Slack Technologies LLC and affiliated companies, contends that Microsoft’s approach harmed competition by using the bundling of Teams to constrain customer choice. A Slack spokesperson characterized the filing as a response to practices that limited options for buyers.

Microsoft did not immediately provide a comment in response to requests.

The new high court proceeding follows a prior regulatory complaint. In 2020 Slack raised concerns with the European Commission, accusing Microsoft of packaging Teams with its Office suite to secure an unfair advantage over competitors. That regulatory engagement culminated last year in an arrangement under which Microsoft pledged reduced prices for Office products that exclude Teams.

This lawsuit was filed during a week that also saw the UK’s Competition Appeal Tribunal certify a group action alleging Microsoft overcharged British businesses for the use of Windows Server software on cloud infrastructure run by competing providers. Microsoft has disputed the claims in that parallel case.


Context and implications

The complaint centers on the allegation that tying and bundling of a widely used collaboration product to a dominant productivity suite can limit customer choice and distort competitive dynamics. The filing cites prior regulatory engagement in Europe and notes a remedial pricing commitment from Microsoft. The company has countered the separate cloud-related allegations currently moving forward in the UK tribunal.

Commercial and market angles

  • The dispute highlights tensions between platform providers that bundle collaboration tools with productivity software and standalone rivals offering specialized messaging services.
  • The timing, coinciding with certification of a mass claim over Windows Server cloud pricing, underscores multiple legal challenges facing Microsoft in the UK market.

Readers seeking valuation context for Microsoft may note that market analyses and tools exist to assess whether Microsoft shares represent value, though this article does not evaluate stock prices or investment strategies.

Risks

  • Legal outcome is uncertain - the High Court case challenges Microsoft’s product packaging and its remedies will depend on judicial findings, affecting enterprise software competition.
  • Parallel litigation - a certified mass claim about Windows Server cloud pricing could create overlapping legal and commercial uncertainty for cloud service providers and enterprise customers.
  • Market and business impacts hinge on judicial or regulatory remedies; any required changes to packaging or pricing could affect enterprise software procurement and vendor strategies.

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