Salesforce and Slack Sue Microsoft in London Over Teams Antitrust

Salesforce, Inc. (NYSE:CRM) and its subsidiary Slack Technologies have filed a legal action against Microsoft Corporation (NASDAQ:MSFT) in London's High Court on April 28, 2026, alleging anticompetitive practices tied to Microsoft Teams, according to Reuters.

Details of the Lawsuit

The lawsuit claims that Microsoft leveraged its dominance in office software to unfairly promote Microsoft Teams, harming competitors like Slack. Alleged practices include bundling Teams with Office 365 and Microsoft 365, making it difficult for customers to choose alternatives.

Company Positions

Microsoft has not yet commented on the lawsuit, but has previously defended its practices, arguing that integration with Office 365 provides added value. Salesforce asserts that these practices stifle competition and innovation.

Precedents and Context

This is not the first time Microsoft has faced such allegations. The European Commission opened an investigation into Teams practices last year. Slack also filed a complaint with the EU in 2020.

Potential Financial Impact

If the court rules in favor of Salesforce, Microsoft could face significant fines or be forced to alter its business practices in Europe. However, it is too early to estimate the exact financial impact. Notably, Salesforce spent $8.87 billion on stock buybacks in the 12 months through September 2025.