As of November 1, 2025, Microsoft Teams is a separate purchase from Microsoft 365 — so the old "Teams is basically free with Office" line needs an asterisk now. Standalone Teams Enterprise starts around $8.55/user/month; bundled into M365 Business Basic it's still effectively $6.
| Entry paid | What comes with it | |
|---|---|---|
| Slack | Pro $7.25/user/mo | unlimited history, unlimited apps, AI summaries/search included |
| Slack | Business+ $12.50/user/mo | compliance, SSO, support SLAs |
| Microsoft Teams | ~$6 bundled (M365 Basic) / ~$8.55 standalone | meetings, and with the bundle: web Office apps |
| Microsoft 365 Business Standard | $12.50/user/mo | Teams + full desktop Office |
Two things actually differentiate them on cost. Slack folds its AI into the plan price — Pro and Business+ subscribers get channel summaries, thread recaps and AI search at no extra charge. Microsoft prices Copilot as a $30/user/month add-on to qualifying M365 plans. If AI-in-chat matters to you, Slack's bundling is a real saving.
The other: with Teams via M365 you're also getting Word, Excel, PowerPoint and Outlook. If your company needs those anyway, Teams is close to free at the margin. If you use [[Google](/entry/arc-is-finished-dia-vs-chrome-vs-the-alternatives-2026) Workspace](/entry/proton-mail-vs-fastmail-vs-google-workspace-for-a-small-business-2026) for documents, that bundle value doesn't apply and Slack vs standalone Teams is a straighter fight — and Slack's app ecosystem, Slack Connect, and developer platform are still meaningfully deeper.
Already all-in on Microsoft 365 with desktop Office: Teams, it's the natural and cheaper choice. On Google Workspace, or you specifically value Slack's integrations and AI-included pricing: Slack Pro at $7.25 is competitive, and Business+ if you need compliance.