Microsoft Teams Chat review and pricing

Microsoft Teams Chat is the messaging surface of Microsoft Teams, launched 2017 as the Microsoft response to Slack and bundled aggressively into Microsoft 365 (formerly Office 365) across the E3, E5, and Business tiers. The product won the bundle war by being included at the seat tier hundreds of millions of buyers already paid; the European Commission opened a formal antitrust investigation in 2023 after a multi-year Slack complaint, and closed the case in 2024 when Microsoft accepted commitments to unbundle Teams from Microsoft 365 in the EU and EEA and to offer Microsoft 365 without Teams at a lower price. Strengths: bundled with Microsoft 365 for the vast majority of enterprise buyers (effectively zero marginal cost for the chat surface), deep integration with Outlook, SharePoint, OneDrive, Office, and the rest of the Microsoft stack, native single sign-on through Azure AD (Entra ID), strong enterprise admin and compliance surface (SOC 2, ISO 27001, HIPAA, FedRAMP High, GCC and GCC High for US government), and unmatched scale at the largest enterprise deployments. Trade-offs: the chat surface remains less polished day to day than Slack, the app integration directory is narrower and less developer-friendly than Slack apps, the product is a sprawling suite (chat plus meetings plus channels plus calling plus shifts) where individual surfaces feel inconsistent, the EU unbundling commitments create a more confusing buying motion in EU and EEA, and post-acquisition complaints inside Microsoft 365 deployments often surface as Teams feeling forced rather than chosen.