Apr 2019
Start of the period covered by the Commission's concerns
The Commission later said its concern that Microsoft tied Teams to its Office 365 and Microsoft 365 business suites covered the period since at least April 2019.
Court case
How the EU antitrust case over Microsoft Teams unfolded
Slack complained to the European Commission in 2020 that Microsoft illegally tied its Teams app to Office 365 and Microsoft 365. The Commission opened an investigation in 2023 and set out preliminary objections in 2024, while Microsoft began selling its suites without Teams. In September 2025 the Commission made Microsoft's commitments binding, which closed the case without a fine.
14 July 2020 to 12 September 2025 · 18 dated events · 12 sources
Where it stands now · as of 1 November 2026
The Commission's 12 September 2025 decision made Microsoft's commitments legally binding and closed both cases without a fine. The commitments run for seven years, and ten years for interoperability and data portability, under a monitoring trustee.
In 30 seconds: the turning points
Stage
1. Complaint
2. Investigation
3. Statement of objections
4. Commitments offered
5. Commitments decision
6. Implementation
Timeline of events
Overview · 14 Jul 2020 to 12 Sep 2025 · click a dot to jump
2019
· · · 15 months later
2020
14 Jul 2020
Turning point
Slack lodges complaint with the European Commission
Slack Technologies filed a complaint alleging that Microsoft illegally tied Teams to its productivity suites, according to the Commission.
22 Jul 2020
Slack makes its complaint public
Slack said Microsoft had force-installed Teams for millions of users, blocked its removal and hidden its true cost from enterprise customers, and asked the Commission to act quickly. These were Slack's allegations.
“We're asking the EU to be a neutral referee, examine the facts, and enforce the law.”David Schellhase, Slack general counsel, Slack Technologies
22 Jul 2020
Microsoft responds to Slack's complaint
Microsoft said it looked forward to giving the Commission more information and argued that Teams had grown because it connected people by video, according to a WBEN report published by Audacy.
“With COVID-19, the market has embraced Teams in record numbers while Slack suffered from its absence of video-conferencing”Microsoft, Audacy (WBEN)
· · · 36 months later
2023
20 Jul 2023
alfaview files a second complaint
The videoconferencing company alfaview GmbH filed a complaint about the same practice. The Commission later handled it in separate proceedings.
27 Jul 2023
Turning point
Commission opens formal investigation, case AT.40721
The Commission opened proceedings to assess whether Microsoft breached Article 102 TFEU by tying Teams to its suites and possibly limiting interoperability with rival tools. It said opening the case did not prejudge the outcome.
“companies are free to choose the products that best meet their needs”Margrethe Vestager, Commission Executive Vice-President, European Commission
31 Aug 2023
Microsoft announces it will unbundle Teams in Europe
Microsoft said it would sell its Microsoft 365 and Office 365 suites without Teams in the European Economic Area and Switzerland from 1 October 2023, at 2 euros a month less, and sell Teams separately to new enterprise customers for 5 euros a month. It also promised more interoperability resources for developers.
1 Oct 2023
Teams-free suites go on sale in the EEA and Switzerland
Microsoft began selling its business suites without Teams in the EEA and Switzerland, Reuters reported. In June 2024 the Commission said it preliminarily found these changes insufficient.
2024
1 Apr 2024
Microsoft extends separate Teams sales worldwide
Microsoft said it would sell Teams separately from Office globally, launching suites without Teams and a standalone Teams product for enterprise customers outside Europe, Reuters reported. The company said the change responded to Commission feedback.
25 Jun 2024
Turning point
Commission sends Microsoft a Statement of Objections
The Commission set out its preliminary view that Microsoft may have abused a dominant position by tying Teams to its suites since at least April 2019, and that interoperability limits may have made this worse. It said a confirmed infringement could bring a fine of up to 10 percent of worldwide annual turnover.
“If confirmed, Microsoft's conduct would be illegal under our competition rules.”Margrethe Vestager, Commission Executive Vice-President, European Commission
25 Jun 2024
Second case opened on alfaview's complaint, AT.40873
The Commission opened a second investigation, Microsoft Teams II, following alfaview's complaint.
25 Jun 2024
Salesforce urges a binding remedy
Salesforce, which by then owned Slack, responded to the Statement of Objections on the day it was announced and called for a quick remedy, in a note added to Slack's 2020 complaint post.
“urge the Commission to move towards a swift, binding, and effective remedy”Sabastian Niles, Salesforce president and chief legal officer, Slack Technologies
2025
16 May 2025
Commission market-tests Microsoft's commitments
The Commission invited comments on commitments offered by Microsoft. They included selling suites without Teams at a lower price, giving customers recurring chances to switch, interoperability for rivals and data export for EEA customers, for seven years or ten years for interoperability and data portability.
16 Jun 2025
Market test closes and Microsoft improves its offer
After the consultation, which ran to 16 June, Microsoft agreed to raise the price difference between suites with and without Teams by 50 percent for some suites and to publish more interoperability information, the Commission said.
2025
Slack and alfaview withdraw their complaints
Both complainants withdrew their complaints after the market test closed on 16 June 2025, according to the Commission, which gave no dates. alfaview said on 12 September 2025 that it had withdrawn a few weeks earlier.
12 Sep 2025
Turning point
Commission makes Microsoft's commitments binding
The Commission accepted Microsoft's commitments in both cases and made them legally binding, which ended the investigations without a fine or a finding of infringement. The Commission said a monitoring trustee would oversee them and that a breach could bring a fine of up to 10 percent of worldwide annual turnover.
“With today's decision, we make binding for seven years or more Microsoft's commitments to put an end to its tying practices”Teresa Ribera, Commission Executive Vice-President, European Commission
12 Sep 2025
Microsoft welcomes the outcome
Microsoft's vice president for European government affairs said the company would turn to implementing the commitments promptly and fully, according to the Financial Times and AFP.
“We appreciate the dialogue with the Commission that led to this agreement.”Nanna-Louise Linde, Microsoft, Channels Television (AFP)
12 Sep 2025
alfaview welcomes the commitments
alfaview's chief executive said the decision would strengthen Europe's digital competitiveness, according to the company's statement.
“For alfaview, a change in practice was always more important than a fine.”Thomas Höppner, alfaview legal counsel, alfaview GmbH via PRLeap
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Sources
12 records, ranked by type- 1Official record27 Jul 2023Commission opens investigation into possible anticompetitive practices by Microsoft regarding Teams (IP/23/3991)European Commission · ec.europa.eu
- 2Official record25 Jun 2024Commission sends Statement of Objections to Microsoft over possibly abusive tying practices regarding Teams (IP/24/3446)European Commission · ec.europa.eu
- 3Official record16 May 2025Commission seeks feedback on commitments offered by Microsoft over possible anticompetitive practices related to Teams (IP/25/1233)European Commission · ec.europa.eu
- 4Official record12 Sep 2025Commission accepts commitments offered by Microsoft to address competition concerns related to Teams (IP/25/2048)European Commission · ec.europa.eu
- 5Subject's own statement22 Jul 2020Slack files EU competition complaint against MicrosoftSlack Technologies · slack.com
- 6News report22 Jul 2020Slack files anti-competitive complaint vs Microsoft in EU
Audacy (WBEN) · audacy.com - 7Subject's own statement31 Aug 2023Microsoft announces changes to Microsoft 365 and Office 365 to address European competition concerns
Microsoft EU Policy Blog · blogs.microsoft.com - 8News report1 Apr 2024Microsoft to separate Teams and Office globally amid antitrust scrutiny (Reuters)
Malay Mail (Reuters) · malaymail.com - 9News report12 Sep 2025Microsoft avoids EU antitrust fine with Teams commitments (AFP)Channels Television (AFP) · channelstv.com
- 10News report12 Sep 2025Microsoft avoids EU fine after competition probe (Financial Times)
The Irish Times (Financial Times) · irishtimes.com - 11Subject's own statement12 Sep 2025EU decides on Teams bundling: alfaview welcomes EU commitments for Microsoftalfaview GmbH via PRLeap · business.mammothtimes.com
- 12News report12 Sep 2025Microsoft Teams dispute resolved five years after Slack complaintGeekWire · geekwire.com
Last updated 1 November 2026. Spotted an error? See corrections. Every event links to the record it comes from. Allegations are attributed to whoever made them.