We only charge for team members that are in a Matter-connected Slack/Teams channel, not the entire workspace.
Who can use this: Workspace Owners and Admins on any paid plan.
For everything on this topic, see the Plans and billing collection. Related articles: How does billing work with multiple channels? and How to cancel or downgrade Matter subscription.
For example, if your workspace has 100 members, but only 20 are in your Matter channel, you would be billed for 20 channel members.