MCC Architecture: The Non-Negotiable Foundation
Every agency managing Google Merchant Center for multiple clients needs a Merchant Center account structure that mirrors how Google Ads uses Manager Accounts (MCCs). In GMC, this is called a Multi-Client Account (MCA) — a parent account that can contain multiple sub-accounts, each representing a separate merchant.
Without an MCA structure, agencies are forced into one of two bad configurations:
- One account, multiple clients: All products in a single feed, compliance issues from one client affecting all others, no clean data separation.
- Separate logins for each client: No centralized access, impossible to manage efficiently, and access is lost when clients leave.
An MCA solves both problems. The parent MCA account gives your agency a single place to access all client sub-accounts, while each sub-account is completely isolated — a suspension in Client A doesn't affect Client B.
Setting Up Your Agency MCA
To create an MCA, you need to request Multi-Client Account access from Google. As of 2026, you can apply through the Google Merchant Center help documentation. Eligibility requirements include managing products on behalf of multiple businesses.
Once approved, you'll see an "Account" dropdown at the top of GMC that lets you switch between the MCA parent view and individual sub-accounts. From the parent view, you can create new sub-accounts for each client — each gets its own unique Merchant ID.
Name sub-accounts with a consistent convention: "[ClientName] — GMC — [Year]". This makes it easy to identify accounts when switching between dozens of clients and keeps your MCA organized as the client list grows.
Account Ownership: Client vs. Agency-Owned
This is the most consequential decision an agency makes about GMC structure, and most agencies get it wrong by defaulting to "agency owns everything" for convenience.
| Model | Pros | Cons | Best For |
|---|---|---|---|
| Agency-owned sub-accounts under agency MCA | Full control, easy access, no client login needed | Client loses account history if they leave; legal gray area on data ownership | Small clients, low-risk categories |
| Client-owned accounts linked to agency MCA | Client retains history; cleaner contract terms; client owns their compliance record | More setup work; client must grant access; harder to maintain MCA-level access if client revokes | Larger clients, high-spend accounts, clients with existing GMC history |
| Hybrid (MCA manages sub-accounts, clients have admin access) | Best of both; clients can see their account, agency has management access | Requires clear user role policies; clients can make changes that break things | Mid-market clients who want visibility |
The practical recommendation: For any client spending over $5,000/month on Google Shopping, set up the GMC account under the client's Google account and link it to your agency MCA. This protects the client's account history, simplifies contract termination (you lose access but the client keeps their data), and avoids situations where the agency is legally holding a client's compliance record hostage.
Specify in your contract who owns the GMC sub-account and what happens to it upon contract termination. Ambiguity here creates disputes. If the agency created the account: will you transfer it to a client-owned account? Will you remove your MCA access? What's the timeline?
Access Management and User Roles
Google Merchant Center offers several access levels. Understanding them prevents both security risks and operational bottlenecks.
GMC User Roles
- Admin: Full access including user management, account settings, and data deletion. Limit to 1-2 people per agency.
- Standard: Can manage products, feeds, and campaigns. Appropriate for account managers and specialists.
- Newsletter only: Receives Google's email updates only. Useful for account executives who need to stay informed without access.
Recommended Access Structure
For a typical agency setup:
- Agency MCA level: Agency founder/director as Admin, plus 1 backup Admin
- Each client sub-account: Account manager as Standard, client primary contact as Admin (for their own account)
- Never give clients Standard or higher access to the agency MCA parent — they should only access their own sub-account
Do not use shared Google accounts ("agency@gmail.com") to manage client GMC accounts. Shared credentials mean you can't audit who made which change, and a single compromised credential gives access to all clients. Use individual Google accounts with proper role assignments.
Who's Responsible for Compliance?
This is where most agency-client GMC relationships break down. Google holds the merchant responsible for compliance — meaning the business whose products are listed. But in practice, the agency controls the feed, the settings, and often the website configuration that determines whether a merchant is compliant.
The Shared Responsibility Reality
Agencies are responsible for:
- Feed accuracy (no price discrepancies between feed and website)
- Policy-compliant ad copy and product titles
- Correct shipping and tax configuration in GMC
- Monitoring the GMC Diagnostics tab for new issues
- Flagging and resolving product disapprovals promptly
Clients are responsible for:
- Website content (return policy, contact page, about page, privacy policy)
- Product pricing accuracy on the live website
- Business legitimacy documentation if Google requests it
- Providing accurate product information for the feed
Include a "GMC Compliance Responsibility Matrix" in your agency onboarding documentation. Clearly list each policy requirement and whether the agency or client is responsible for maintaining it. This prevents blame-shifting when a suspension hits and sets clear expectations upfront.
Proactive Compliance Monitoring
Build a weekly review of all client sub-accounts into your agency workflow. The GMC Diagnostics tab shows account issues, product disapprovals, and policy warnings. At scale, check this across all clients using the MCA-level view — you can see an aggregated issues dashboard without logging into each sub-account individually.
Consider using GMC Unbanned's free scanner as part of your monthly compliance audit for each client. It catches website-level compliance issues (missing policies, contact information problems, price discrepancies) that the GMC interface itself doesn't always surface clearly.
Suspension Isolation: Protecting Other Clients
The most feared question in agency GMC management: "If one client gets suspended, does it affect my other clients?" The answer depends on your account structure.
What Does Propagate Between Accounts
- Business verification failures: If your agency's business identity can't be verified, it can affect sub-accounts where the agency is listed as the account owner
- Policy violations tied to your agency identity: If Google determines your agency is knowingly submitting non-compliant products across multiple clients, they can act on the MCA level
- Repeated misrepresentation patterns: Google can identify patterns across accounts managed by the same entity
What Does NOT Propagate
- A single client's misrepresentation suspension from a website-level issue does not automatically suspend other client sub-accounts
- Product disapprovals in one sub-account don't affect products in another
- Feed errors in one account are isolated to that account
If you're managing accounts that sell similar products across multiple clients (e.g., multiple dropshipping clients in the same category), Google may identify patterns. This isn't documented policy, but agencies have reported MCA-level restrictions after multiple sub-accounts had repeated policy violations. Maintain genuine compliance for every client — don't treat policy compliance as optional for lower-spend accounts.
When a Client Gets Suspended
- Don't panic: Isolate the issue to that sub-account — confirm other accounts are still running normally
- Notify the client immediately: Transparency is critical; delays make appeals harder
- Run a full compliance audit: Check their website, feed, and account settings before filing any appeal
- Fix first, appeal second: Appeals with unresolved issues always fail
- Use the GMC Unbanned scanner: It identifies the specific compliance gaps causing most suspensions
- Document your fix for the appeal: Specific, detailed appeals with evidence of what changed perform significantly better
See our full suspension appeal guide for the complete appeal process and what Google's reviewers look for.
Feed Management at Scale
Managing product feeds for dozens of clients requires systematized approaches. Ad-hoc feed management doesn't scale — each client ends up with a unique setup that requires individual attention when something breaks.
Standardized Feed Infrastructure
Build a standard feed template for common client platforms. For each platform you commonly support, maintain:
- A canonical attribute mapping (platform field → GMC attribute)
- A standard feed schedule (how often to refresh, what time)
- A monitoring alert (email notification for fetch errors)
- A quality checkpoint (minimum required fields, acceptable missing % for optional fields)
For Shopify clients, the Google & YouTube app is your baseline. Augment it with a supplemental feed for title optimization and custom labels. See our Shopify GMC setup guide for details.
For WooCommerce clients, use the official Google Listings & Ads plugin as a baseline, then add WP All Export or a custom feed for more control over attribute optimization.
Supplemental Feeds: The Agency Superpower
Supplemental feeds let you add or override attributes in a primary feed without modifying the client's website or plugin. This is critical for agency scalability:
- Add custom labels (for campaign segmentation) without client involvement
- Override titles with optimized versions without changing the client's website
- Add GTINs for products where the primary feed is missing them
- Apply product_type hierarchies consistently across all client products
Maintain a supplemental feed spreadsheet for each client. Use Google Sheets with automatic publishing to a CSV URL. GMC can fetch this directly on a schedule. Your team can update custom labels, title improvements, and GTIN additions from one spreadsheet without touching the client's platform or primary feed.
Agency Client Onboarding Checklist
Run this checklist for every new client before launching Shopping campaigns:
Week 1: Account Setup
- ☐ Create or claim sub-account in agency MCA
- ☐ Verify business info (name, address, phone, website)
- ☐ Claim and verify website (HTML tag or DNS method)
- ☐ Set up shipping zones covering all target markets
- ☐ Configure tax settings for relevant regions
- ☐ Link to client's Google Ads account (or create)
- ☐ Run GMC Unbanned scan to identify website compliance gaps
Week 1: Website Compliance Verification
- ☐ Return policy page exists, is accessible, clearly states timeframes and conditions
- ☐ Contact page with physical address, email, and phone (or contact form)
- ☐ About/who-we-are page with business identity signals
- ☐ Privacy policy page (required for any data collection)
- ☐ HTTPS across all pages
- ☐ Prices on website match GMC feed prices (including currency)
- ☐ No product pages returning 404s that are in the feed
Week 2: Feed Setup and QA
- ☐ Primary feed configured and fetching successfully
- ☐ All required attributes populated (id, title, description, link, image_link, price, availability, condition)
- ☐ GTINs present for all products where available
- ☐ Brand attributes populated
- ☐ Product categories (google_product_category) assigned
- ☐ Supplemental feed created for custom labels and title optimization
- ☐ Less than 5% of products in "Pending" or "Disapproved" status
Client Offboarding Without Losing Account History
Client transitions are inevitable. The cleanest offboarding preserves the client's account history while removing your agency's access.
If the Account Is Agency-Owned (Sub-Account Under Agency MCA)
- Add the client (or their new agency) as an Admin user in the sub-account
- Have the client verify they can access it with their credentials
- Transfer sub-account ownership to the client's standalone GMC account: GMC doesn't have a "transfer" button — you'll need to recreate the account under their ownership and migrate the feed configuration
- Export the feed configuration, shipping settings, and custom label structure as documentation for the new account
- Remove your MCA's access from their standalone account
If the Account Is Client-Owned (Linked to Agency MCA)
Much simpler: remove the MCA link from the client's account settings, or have the client revoke your access. Their account continues normally — all product history, review history, and account age transfer with them.
For any client spending over $5,000/month or running campaigns for more than 6 months, strongly encourage client-owned account structure from day one. The cost of account migration when they leave (losing review history, restarting the trust-building process) is much higher than the minor setup inconvenience of the client-owned model.
Cross-Client Reporting
One of the biggest operational benefits of the MCA structure is aggregated reporting. From the MCA parent account, you can see performance metrics across all sub-accounts without logging into each one individually.
MCA-Level Dashboards
The MCA overview shows:
- Total product count across all sub-accounts
- Accounts with active issues or warnings
- Aggregate impressions and clicks (when linked to Google Ads)
For more sophisticated cross-client reporting, use the Content API for Shopping to pull product status data programmatically. This lets you build dashboards showing disapproval rates, feed health scores, and account status across all clients in a single view. Google's Content API documentation has detailed setup guides.
Client-Facing Reporting
Clients typically want to see:
- Product approval rate (% of products approved vs disapproved)
- Shopping impression share and impression volume
- Click-through rate from Shopping results
- Conversion rate from Shopping clicks
- Feed quality score trends
Build a monthly GMC health report template — even a simple one. Clients who understand their account health are less likely to make unilateral website changes that trigger compliance issues and more likely to engage with your recommendations.