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Salesforce and Slack Sue Microsoft in UK Over Teams Competition Claims

By  |  April 27, 2026

Salesforce and its workplace messaging platform Slack have filed a lawsuit against Microsoft at London’s High Court, alleging anticompetitive conduct to the tech giant’s Teams application.

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    According to Reuters, Slack Technologies and affiliated entities lodged the claim on April 23, arguing that Microsoft’s business practices restricted fair competition in the workplace communication software market. A Slack spokesperson said the case was brought “because Microsoft’s practices harmed competition, ⁠using tying and bundling of Teams to limit customer choice.”

    The dispute centers on Microsoft’s integration of its Teams collaboration software into its Office suite, a strategy Slack has long criticized. Per Reuters, Slack first raised concerns in 2020 when it filed a complaint with the European Commission, accusing Microsoft of bundling Teams with its Office products to secure an unfair advantage over competitors.

    The European Commission examined the issue, and according to Reuters, Microsoft avoided a potentially significant fine last year by agreeing to adjust its pricing structure. The company committed to offering lower prices for Office packages that exclude Teams, a move intended to address competition concerns raised by regulators.

    Related: Salesforce Bets Big on AI Future With $8 Billion Informatica Acquisition

    The newly filed lawsuit comes amid broader scrutiny of Microsoft’s market practices in the United Kingdom. Per Reuters, the case was initiated in the same week that London’s Competition Appeal Tribunal approved a separate mass legal action alleging Microsoft overcharged British businesses for using Windows Server software on rival cloud computing platforms. Microsoft has denied those allegations.

    The High Court case marks another escalation in the ongoing rivalry between Slack and Microsoft, highlighting continued tensions in the rapidly evolving market for workplace communication and productivity tools. According to Reuters, the outcome could have implications for how large technology firms package and sell integrated software services in Europe and beyond.

    Source: Reuters