If you allow it, your Google Chat users can chat with people outside your organization.
To use Google Chat, users outside your organization need a Google Account. They need to be a G Suite user, or have an account that ends with @gmail.com or a non-Gmail Google Account. If the external contact is a G Suite user, their administrator needs to turn on Google Chat for their organization. Otherwise they won’t receive an invite and won't be able to join the room or reply to direct messages.
How external chat works
- Chat respects the Chat externally setting for your organization.
- For privacy and abuse protection, when you add an external user to a message or room, they'll be invited instead of directly added. Invited users get an email invitation and their Chat roster and "Browse rooms" screen show they were invited. Users can block and report someone if they get unwanted messages.
- External users can't add members, rename rooms, or add webhooks in rooms.
- Only G Suite users can create rooms or messages. External users without G Suite accounts can only participate in the messages and rooms they're invited to join by a G Suite user.
- Users in G Suite organizations that haven't turned on Chat aren't reachable through Chat. Users can message any external users in organizations that have Chat turned on.
- You can't turn an existing room into an external room. To create an external room, you'll need to recreate existing rooms and add external users.
- You can't add an external user to direct messages with a group. You can only chat externally with a 1:1 direct message or in a room.