A manager account — Google's current name; the old name My Client Center survives in the abbreviation MCC — is a Google Ads account that contains no campaigns. Its job is links: to client accounts and to other managers, forming a tree. One sign-in at the top of the tree reaches everything beneath it, with users, billing and reporting manageable across the lot. It is the org chart of Google Ads — and org charts decide who sees what, which is why the MCC matters twice as much once an AI is attached to a login.
How the MCC hierarchy works
The hierarchy is a tree with rules:
- Managers link accounts; they do not own them. A client account keeps its own users and can be linked to several managers at once.
- Sub-managers nest. Large agencies build layers — a top manager, sub-managers per team or region, client accounts at the leaves.
- Access flows downward. A user added to a manager account holds that role across every account below it — the ones linked today and the ones linked next year. Permission inheritance is the feature, and the thing people forget they granted.
- Roles still apply. Admin, standard and read-only access are set at the manager and inherited down.
The practical consequence: "what can this login touch?" is answered not by the login's own account list but by the union of every manager grant it holds.
Common MCC mistakes agencies still make
One shared login for everything — a bad idea that predates AI, and attaching an assistant to it makes the blast radius conversational. Connecting the top of the tree when the work needs two leaves. Nobody pruning: departed staff with inherited manager access, client accounts still linked after the engagement ended. And confusing linking with owning — clients can and do link other managers, so your MCC view is not the full list of who reaches the account.
What an AI connector inherits from the MCC tree
An AI connector runs under a signed-in Google login, so it inherits exactly that login's union of grants. Connect at manager level and one conversation can traverse every client the login reaches — pull spend across forty accounts, compare them, and, with approval, change them. That is the genuinely new capability: cross-account work in a single thread used to be an export-and-spreadsheet afternoon.
It is also the reason scoping exists. The sane pattern for teams: each member signs in with their own Google account and receives their own connector; the organisation can narrow — never widen — what each member's connector reaches, down to named customer IDs; and every call lands in an audit trail under that member's name. The MCC decides the maximum an assistant could reach; the connector layer decides what it actually does. The agency setup is built on that distinction, and the agencies and teams page covers linking and scoping in one pass.