GUIDE · April 2, 2026 · 7 min read

How to Migrate Slack to Microsoft Teams

Your company decided to switch from Slack to Microsoft Teams. But your team has years of conversations, shared files, and institutional knowledge locked in Slack channels. Here's how to bring it all to Teams without losing anything.

What Can Be Migrated

Channels — Slack channels become Teams channels
Messages — message text, timestamps, and sender attribution
Files — files shared in channels are migrated to the Teams channel's SharePoint folder
User mapping — map Slack users to Microsoft 365 users

What Cannot Be Migrated

Direct messages (DMs) — Microsoft's import API only supports channel messages
Slack apps/bots — custom integrations need to be recreated in Teams
Reactions and threads — thread structure is flattened into chronological order
Slack Connect (external channels) — external participants need to be re-invited

Prerequisites

Slack: Workspace admin access or a Slack app with channels:read, channels:history, users:read scopes
Teams: Azure AD app with Teamwork.Migrate.All application permission (admin consent required)
User mapping: A list matching Slack usernames to Microsoft 365 UPNs

Migration Steps

1. Connect Slack and Teams credentials in MigrationFox

2. Select the source team/workspace and channels to migrate

3. Configure user mapping (source email → destination email)

4. Choose or create the destination team in Microsoft Teams

5. Start the migration — MigrationFox creates channels and imports messages

Files shared in Slack channels are automatically migrated as companion file jobs to the backing SharePoint site.

Compliance Considerations

Messages are imported with original timestamps using Microsoft's Teams Migration API. This preserves the timeline for compliance and audit purposes. However, messages show as "imported" rather than native — this is a Microsoft API limitation.