This document explains the different terms used to describe accounts in the
Google Ads API and how they relate to each other.

## Overview

The Google Ads API uses several terms to describe accounts, which can sometimes lead to
confusion. Understanding these distinctions is important for managing accounts
and interpreting API responses.

## Account types

The following definitions clarify the different account types you will encounter
when working with the Google Ads API.

### Manager account

A **manager account** is a primary account used to manage multiple Google Ads
accounts.

- **Former name:** This was formerly known as "MCC" (My Client Center). You may still see this term in legacy documentation or discussions.
- **Purpose:** Use a manager account when you want to link to and manage multiple accounts through a single hierarchy.
- **API representation:** Identified by a [`Customer`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer) resource where [`customer.manager`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer#manager) is `true`.

### Advertiser (serving) account

An **advertiser account** (or **serving account**) is an individual Google Ads
account that runs ad campaigns.

- **Purpose:** This is where campaigns, ad groups, asset groups, and ads are created and served.
- **API representation:** Identified by a [`Customer`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer) resource where [`customer.manager`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer#manager) is `false`.

### Client account

A **client account** is any account (either an advertiser account or another
manager account) that is linked to and managed by a superior manager account
within the hierarchy.

- **Context:** The term "client" refers to the relationship in the hierarchy (managed by a manager), not necessarily a "client" in the business sense.
- **API representation:** Query [`CustomerClient`](https://developers.google.com/google-ads/api/reference/rpc/v26/CustomerClient) to inspect accounts in a manager's hierarchy, and use [`CustomerClientLink`](https://developers.google.com/google-ads/api/reference/rpc/v26/CustomerClientLink) to manage links between manager and client accounts.

### Customer

In the API context, a **Customer** is the resource representing *any* Google Ads
account, whether it's a manager account or an advertiser account.

- **Representation:** All accounts are represented by a [`Customer`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer) resource, identified by a `customer_id`.
- **Role:** The nature of the account (manager or serving) depends on the specific resource.

### Test account

[Test accounts](https://developers.google.com/google-ads/api/docs/best-practices/test-accounts) are special advertiser accounts organized under a
dedicated **test manager account** specifically for testing API integrations.
Both the test manager account and the test advertiser accounts under it have
their [`customer.test_account`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer#test_account) field set to `true`. Test
accounts cannot be created under a production manager account.

- **Purpose:** Test accounts allow you to test API calls without serving live ads or incurring costs. They don't serve live ads.
- **API representation:** Identified by a [`Customer`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer) resource where [`customer.test_account`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer#test_account) is `true` (with [`customer.manager`](https://developers.google.com/google-ads/api/reference/rpc/v26/Customer#manager) distinguishing a test manager account from a test advertiser account).

## Hierarchy example

A typical hierarchy looks like this:

- **Manager Account A** (Top level)
  - **Client Account B** (Advertiser account)
  - **Client Account C** (Another manager account)
    - **Client Account D** (Advertiser account)

In this example:

- Account A is a manager account.
- Accounts B, C, and D are client accounts relative to their parents.
- Accounts B and D are advertiser (serving) accounts.
- Account C is both a client account (to A) and a manager account (to D).