Who can change the people in a Channels conversation?

A channel manager can add or remove active Account members from a channel. Account owners and admins can also manage a public or private channel they have joined. Direct conversations have fixed membership. A different audience needs a separate conversation.

A group conversation requires a conversation manager to add people, remove other participants, or change participant roles. Members can leave their own group conversation, subject to the last-manager rule below. An Account owner or admin role does not by itself grant group-management access. Account membership and conversation membership are separate: someone who is not in the Account must first be admitted to the Account.

Adding a person to a private channel lets them read its existing history and future messages. Removing them prevents further service access to the private channel, but cannot erase copies they already retained.

Removing someone from an open channel does not exclude them from reading it if they remain an active, non-guest Account member. They can discover it and join again. Private conversations restrict access to their members.

The last manager cannot leave or be demoted until another manager has been assigned. Membership in the Account's default workspace-wide channel cannot be removed through channel controls. These protections may explain a refused removal even when a control is visible.

A mention or shared message link does not substitute for membership.

Add, remove, or change a participant

1. Confirm the Account and conversation. Review the existing history before expanding its audience.
2. Open the conversation actions and choose People in conversation.
3. To add someone, select Add people, select the intended active Account members, and confirm Add people.
4. To change a participant's role, use Channel role for that person and choose Member or Manager.
5. To remove a participant, select their Remove control and confirm the named person.
6. Reopen People in conversation and confirm the resulting participants and roles. If a batch addition fails partway, keep the additions that succeeded and retry only the missing people.

To leave an eligible conversation, open Conversation settings and choose Leave channel. If you are its last manager, first assign another participant as Manager and confirm that saved role. The Mac app may show group-management controls to a joined Account owner or admin; the service still requires that person to be a conversation manager.