Slack files EU antitrust complaint against Microsoft

Slack accuses Microsoft of violating EU competition law.

Last updated:

In a complaint filed before the European Commission, the EU’s top competition regulator, Slack has accused Microsoft of antitrust violations for tying its Teams to Microsoft Office products.

Slack is accusing Microsoft of forcing Office users to install Teams, blocking its removal, and hindering interoperability with rivals.

While Slack is available as a standalone service and application with various pricing tiers, Microsoft Teams comes as part of an Office 365 subscription, though there is a free version of Teams available as well.

Slack is asking the EU to force Microsoft to sell Teams as a standalone product, rather than bundling it with Office.

Jonathan Prince, Vice President of Communications and Policy at Slack said:

We’re confident that we win on the merits of our product, but we can’t ignore illegal behaviour that deprives customers of access to the tools and solutions they want,

Slack threatens Microsoft’s hold on business email, the cornerstone of Office, which means Slack threatens Microsoft’s lock on enterprise software.

Prince added that Slack is asking for a level playing field that can enable healthy competition, proceeding to call out similarities between his company’s product and Teams, which launched after Slack picked up momentum as the “cool” workplace chat tool.

Microsoft is reverting to past behaviour. They created a weak, copycat product and tied it to their dominant Office product, force installing it and blocking its removal, a carbon copy of their illegal behaviour during the ‘browser wars.

Slack is asking the European Commission to take swift action to ensure Microsoft cannot continue to illegally leverage its power from one market to another by bundling or tying products.

Slack has only filed a complaint for now — the next step will be for the EC to decide whether to open a formal investigation.

Rapid Mobile

Rapid Mobile uses cookies, tokens, and other third party scripts to recognise visitors of our sites and services, remember your settings and privacy choices, and - depending on your settings and privacy choices - enable us and some key partners to collect information about you so that we can improve our services and deliver relevant ads.


By continuing to use our site or clicking I Accept, you agree that Rapid Mobile and our key partners may collect data and use cookies for personalised ads and other purposes, as described more fully in our privacy policy.


You can change your settings at any time by clicking Manage Settings or by visiting our Privacy Centre for more detailed information.


Privacy Settings saved!
Cookie Services

When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies.Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.

These cookies allow us to count visits and traffic sources, so we can measure and improve the performance of our site.

We track anonymized user information to improve our website.
  • _ga
  • _gid
  • _gat

Decline all Services
Accept all Services