Is there any additional cost to adding members to a Trello board with a Trello Premium account?

I pulled my reply through the bot to be sure and it says and summarizes as follows:

Your summary is accurate and aligns with Atlassian's official documentation:

• Workspace admins/members: Both roles are billable. There is no difference in billing between a workspace admin and a workspace member—they both consume a paid seat How billing works with Trello Premium and Standard | Trello | Atlassian Support.

• Board admins/members:

  • If they are already workspace members, they are not billed additionally for being on a board.

  • If they are "non-workspace single-board guests" (not a workspace member and only on one board in the workspace), they are free, including if they are set as observers Add an observer to a board | Trello | Atlassian Support.

  • If they are "non-workspace multi-board guests" (not a workspace member but on two or more boards in the workspace), they are billed at the same rate as workspace members Multi-board guests | Trello | Atlassian SupportWhat is a Workspace guest? | Trello | Atlassian Support.

This covers all the key billing scenarios for Trello Premium workspaces.

Hope that helps.

I always struggle with this phrasing overlap, so I double checked. I should paste this somewhere.