Slack vs Microsoft Teams for a 12-person company

Not ‘which is better,’ but which one creates fewer expensive habits: notification debt, file sprawl, and guest-access chaos.

If you already pay for Microsoft 365, Teams can feel “free.” If you live in Google Workspace, Slack can feel inevitable. The real comparison is how your team communicates under stress: incidents, launches, support escalations.

Hidden issues we look for

  • Search quality across messages and files once history grows.
  • Guest access models when clients and agencies need limited visibility.
  • Mobile realities for founders who approve things between meetings.

Verdict (starter)

Teams wins when your world is already files-in-SharePoint and meetings-in-Outlook. Slack wins when channels are your system of record and integrations matter more than bundled meetings.

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