The European Commission has been investigating Microsoft's tying of Office and Teams since a complaint by Salesforce-owned competing workspace messaging app Slack in 2020. Teams, which was added to Office 365 in 2017 free of charge to users, became popular during the pandemic due in part to its video conferencing. Rivals, however, said packaging the products together give Microsoft an unfair advantage. The company started selling the two products separately in the EU and Switzerland on August 31 last year.