Before you sign

How to check if a Google MCM partner is genuine

You can check any Google MCM (Multiple Customer Management) partner yourself in about ten minutes, without trusting a sales deck. Look them up in Google's own sellers.json, open their sellers.json, match the ads.txt line they ask for, and read the delegation type and revenue share in the Ad Manager invite.

By Umashankar Kushwah · Published 1 October 2026

Step 1: Are they in Google's sellers.json?

Google publishes its sellers.json at realtimebidding.google.com/sellers.json, and says MCM parent publishers are listed there as intermediaries. Search the file for the partner's company name or domain. If a company says it is an MCM parent and you can't find it, ask it to show you its entry.

Tip: the file is large. Open it in a desktop browser and use Ctrl+F (Cmd+F on Mac).

Step 2: Does their own sellers.json list a seller ID for you?

Google requires Manage Inventory parents to submit a seller ID for each child publisher, and says that ID must appear in the parent's sellers.json and in your ads.txt. Open partnerdomain.com/sellers.json. After onboarding, your domain should be listed there with the seller ID they gave you.

If the file returns 404, the company publishes none. That is an answer in itself.

Step 3: Does the ads.txt line match?

Google's seller-ID help page shows the parent's line as DIRECT, carrying the seller ID assigned to you, with Google listed as RESELLER. Check two things: the seller ID in the line matches the one in their sellers.json (step 2), and the Google publisher ID they give you is the one listed for them in Google's sellers.json (step 1).

Step 4: Read the invite inside your Ad Manager account

The invitation arrives in your own Ad Manager account and states the delegation type. For Manage Account, the revenue share (0% to 100%) is set in the invitation itself, so read it before you accept. Under Manage Inventory the partner gets no access to your account at all.

What are the red flags?

  • Guaranteed or instant approval. Google reviews every child site and app. No partner can promise the result.
  • An upfront fee. In my view a fee before any revenue is a reason to walk away.
  • Asking for your Google login or password. Manage Account works through delegated access and Manage Inventory needs no access at all. Neither needs your password.
  • No entry in Google's sellers.json, or no sellers.json on their own domain.
  • Won't put revenue share and payment terms in writing.

Is a Google Certified Publishing Partner the same as an MCM parent?

No. To be an MCM parent, a company needs Google Ad Manager 360. Google Certified Publishing Partner (GCPP) is a separate Google programme with its own directory. Plenty of MCM parents are not GCPPs. AdxDesk is not a GCPP either, and says so on every page.

Check partners against measured data

The Google MCM partners directory lists 199 companies with counts taken from their own sellers.json files. How AdxDesk measures partners explains the method step by step. To see who actually works with Indian sites, start at Google MCM partners for Indian sites.

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