Slack didn’t hold back in antitrust case against Microsoft Teams

23 Jul 2020

Image: © Sundry Photography/

Slack has accused Microsoft of bundling its Teams workplace messaging app with Office 365 products to give it an unfair advantage.

Two of the most commonly used tools for workforces since the outbreak of the coronavirus pandemic are set to come head to head, after workplace messaging app Slack filed an EU antitrust case against Microsoft over its rival messaging product, Teams.

Slack has accused Microsoft of being engaged in an “illegal and anti-competitive practice” by bundling Teams with its Office 365 enterprise suite in a way that is designed to eliminate rivals, which would be a breach of the European Commission’s antitrust rules.

This includes accusations of “force installing it for millions, blocking its removal, and hiding the true cost to enterprise customers”.

“This is much bigger than Slack versus Microsoft,” said Jonathan Prince, Slack’s vice-president of communications and policy. “This is a proxy for two very different philosophies for the future of digital ecosystems, gateways versus gatekeepers.

“We want to be the 2pc of your software budget that makes the other 98pc more valuable; [Microsoft] want 100pc of your budget every time.”

Microsoft cuts no slack

Slack’s general counsel, David Schellhase, added that the company wants fair competition and “a level playing field” and accused Microsoft of “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’,” Schellhase said.

“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.”

Microsoft was previously fined €561m by the EU for failing to uphold an antitrust ruling to offer a selection of competitor browsers for users upon installing the Windows operating system.

In a statement seen by TechCrunch, a spokesperson for Microsoft said: “We created Teams to combine the ability to collaborate with the ability to connect via video, because that’s what people want.

“With Covid-19, the market has embraced Teams in record numbers while Slack suffered from its absence of video conferencing. We’re committed to offering customers not only the best of new innovation, but a wide variety of choice in how they purchase and use the product. We look forward to providing additional information to the European Commission and answering any questions they may have.”

In June, Slack and Amazon announced that they forged a multi-year agreement to provide communication tools to distributed teams, in a move that was seen as a way to take on Microsoft Teams.

In an interview with the Verge in May, Slack CEO Stewart Butterfield said: “Microsoft is perhaps unhealthily preoccupied with killing us, and Teams is the vehicle to do that.”

Colm Gorey was a senior journalist with Silicon Republic