What is the best way for GMC for a marketing agency?
Hello, we are a marketing agency handling multiple GMC accounts for clients. What is the best way to do it – convert to an advanced account or have a separate account for every business? Also, do I need to have the same gmail address to link Google Ads and GMC accounts?
The short answer is:
The best way for your marketing agency to manage multiple Google Merchant Center (GMC) accounts is to request a Multi-Client Account (MCA), which is Google’s “advanced account setup” for agencies and multi-brand retailers.
This centralizes management, linking, and user access while keeping each client’s GMC separate for policy enforcement.
You absolutely do not need to use the same Gmail address to link Google Ads and GMC accounts; the link is done by sending a request from the GMC admin to the Google Ads account, where any admin can approve it.
For managing product data reliably at scale, the best long-term solution is to implement an automated system using the Google Ads API and the Content API for Shopping (which is being replaced by the Merchant API), ideally facilitated by a GTM Server Container setup with a host like Stape.
The long answer is:
Your situation is exactly what the Google Merchant Center Multi-Client Account (MCA) is designed for.
Requesting an MCA from Google will convert your primary GMC into a parent account, under which all your clients’ individual GMCs become sub-accounts.
This structure gives your agency a single point of access to manage all clients, review policies, and approve account linking requests without having to log in and out of dozens of separate accounts.
It’s cleaner, more efficient, and is the standard practice for agencies.
The key benefit is that while your management is centralized, each client’s product catalog and website verification remain separate, which is vital for maintaining compliance with Google’s policies and preventing one client’s policy violation from negatively impacting all others.
Regarding linking accounts, you do not need the same email address for Google Ads and GMC.
You will simply go into the client’s sub-GMC account, navigate to the Linked Accounts section, and send a link request to their specific Google Ads Customer ID.
Any user who has administrative access to that Google Ads account can approve the request from their notifications tab, regardless of their email address.
This separation of login credentials is a standard security measure for agencies and clients.
For product feed management, your current method of manual or platform-based uploads will become a bottleneck as you scale.
This is where an advanced solution using APIs and a server-side tagging environment becomes excellent and cost-effective.
The core of this solution involves using the Google Ads API for managing campaigns and the Content API for Shopping (or the new Merchant API) for product data.
The Content API allows you to send product, price, and inventory updates directly to GMC in real-time.
This is far more robust and faster than relying on traditional file-based feeds, reducing the risk of product disapprovals due to outdated information.
To streamline this complex data flow, you can implement a Google Tag Manager (GTM) Server Container solution.
By sending all event data, including product view and purchase information, to your GTM Server Container endpoint, you can then use a custom tag or client to fire both the Google Ads API calls and the Content API calls from one centralized, server-side environment.
This server-side tagging implementation bypasses client-side restrictions (like ad-blockers and browser limitations), giving you cleaner conversion data for Performance Max campaigns (the Google Ads API part) and ensuring real-time product data accuracy (the Content API part).
Hosting the GTM Server Container is typically cheap and scalable with providers like Stape or through self-hosting on a low-cost virtual machine on Google Cloud Platform or a similar cloud service.
This setup is superior because it centralizes all data collection and distribution, ensures data quality, and provides your agency with a professional, scalable infrastructure for every client under your new MCA.
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