Adding observer to Trello board

[Todd Howe]

I am trying to add an observer to one of my Trello boards and it is telling me they have that they must be a member of my workspace, and then it wants to charge me.  Did this change recently.  We have 5 paid members and roughly 30 observers, and this has not happened before.

[Sal]

Hi @Todd Howe! If the Observer you're trying to add already has access to another board within your Workspace, they'll be considered a multi-board Guest (Observers are Guests of a Workspace with fewer permissions compared to regular Guests), which are considered billable members for your Trello subscription. 

You can always refer to this support article to understand more about which types of members are considered billable members on Trello: https://support.atlassian.com/trello/docs/how-billing-works-with-trello-premium-and-standard/#When-is-a-member-billable.

I hope that answers your question!