Hey @Nicolette Godlove
Jacques here from Intercom Support. I hope all is well today!
When you send a conversation response in Intercom to someone other than the original user, the conversation's linked user can change, and all conversation details are visible to the new recipient. Intercom is designed so that all participants in a conversation (including new recipients you add) can see the full conversation history, unless you use internal notes (which are only visible to teammates). There is no built-in way to restrict visibility of certain conversation parts from specific participants within the same conversation. If you add a client to a conversation, they will see the full thread. If you reply to a different recipient (e.g., the client) and remove the original user, the conversation will still include all previous messages unless you start a new conversation.
The only way to prevent the client from seeing details meant for the original user is to start a separate conversation with the client, but this means the client will not see the original thread. There is no setting to change this behavior or to easily switch the linked user without exposing the conversation history to the new recipient. Internal notes can be used for teammate-only communication, but not for hiding parts of the conversation from external participants.
So if you add a new recipient to a conversation in Intercom, they will see the full conversation history. There is no way to restrict this or to change the linked user without exposing the thread. The only workaround is to start a new conversation for private queries.
Hope this helps!