Microsoft is facing a significant antitrust fine from the European Commission for allegedly bundling its Teams chat and video app with its Office 365 suite, disadvantaging competitors like Slack. This marks the most serious charges against Microsoft since a €561 million fine in 2013. The use of Teams surged during the pandemic, growing from 20 million users in 2019 to 300 million in 2023. The Commission's investigation, prompted by Slack's 2020 complaint, found Microsoft dominant in the professional software market and raised concerns over unfair competitive advantages. Despite Microsoft's efforts to unbundle Teams in Europe, regulators deemed these steps insufficient. Microsoft is now seeking further solutions to address these concerns.