Give clients access to their workspace

From a client's workspace, go to Settings and use Client logins to invite people from that company. They join as Viewer (look only): they see everything in their own workspace but can't change flags, and they never see your other clients.

If a client wants to take over their workspace, you can hand it over. The workspace becomes the client's own account and keeps its data. Your agency's connections are removed, so the client reconnects with their own logins and chooses their own plan.