If your agency runs Google Shopping for several clients out of Poland, August 24, 2026 added a task to your list: Google overhauled Merchant Center reporting, and the change reaches back to rewrite historical data starting July 1, 2026. Any report you already sent a client for July or August may no longer match what the dashboard shows today, even though absolutely nothing changed inside the campaigns or account settings themselves the whole time.
For an agency accountable to multiple clients for accurate numbers, this is not a one-time fix. It is a reason to go through every Merchant Center account in your portfolio and make sure each client understands where a discrepancy is coming from before they ask you directly.
What Changed, Technically
- YouTube affiliate sales are no longer counted inside organic traffic - they now sit in their own interaction type.
- The definition of YouTube organic traffic itself was updated.
- Product-level reporting now includes every Google Ads format at once: Performance Max, Video, App, and Demand Gen.
- New segmentation options were added for finer breakdowns.
All four changes applied automatically, with no opt-out, and cover historical data going back to July 1, 2026.
This Week's Checklist for Your Agency
- Go through every client's Merchant Center account and record current July-August figures as the new baseline - saved reports from before August 24 no longer reflect the current methodology.
- Find the YouTube affiliate share in any account with active YouTube ad spend, and prepare an explanation if it differs noticeably from the previous organic figure.
- Check whether a client runs multiple ad formats at once (Performance Max plus Video or Demand Gen) - the new product-level report now shows them combined, which may shift optimization priorities.
- Draft one short standard explanation of the methodology change to send clients, instead of writing a custom reply the first time someone asks about a "drop."
- Separately review the merged Shopping ads policy Google is introducing in September 2026 - for clients with a large catalog, this could affect which products stay listed.
Why Discrepancies Are Not Cause for Alarm
The key point for a client conversation: a shift between reporting categories is not lost revenue and not an account problem. It is a change in how Google counts, not in what actually happened. Real sales and revenue do not depend on which column of a report an interaction lands in.
The same underlying logic sits behind AdSense's recent measurement shift - see our breakdown of AdSense's move to begin-to-render counting starting February 2027 to understand the wider pattern of Google tightening measurement across its ad ecosystem.
How to Structure the Check Inside the Agency
If several account managers handle different Merchant Center clients, it helps to put one person in charge of the initial pass across the whole portfolio for discrepancies after August 24, rather than leaving it to each manager individually. That speeds up catching cases where a gap goes beyond what the category shift explains, and it avoids different team members giving clients inconsistent explanations of the same change.
A Note on Timing Your Client Reports
Agencies sending monthly performance summaries in the first week of September should consider pushing that report by a few days rather than sending it exactly on schedule with unstabilized post-change numbers. A short delay to let the new methodology settle is easier to explain than a report that needs a follow-up correction a week later once the picture is clearer.
FAQ
Do we need to enable the new reporting manually in each account? No, the changes apply automatically to every Merchant Center account with no setup needed from the agency or client.
What is a quick way to explain the discrepancy to a client? Something like: "Google changed how Merchant Center counts reports retroactively from July 1 - your actual sales did not change." That covers it without a long technical explanation.
Should campaign KPIs be recalculated because of this? Only if a KPI was tied specifically to the share of organic YouTube traffic. Otherwise the category shift does not require revisiting targets.
Does this affect every Merchant Center account equally? It applies to all accounts technically the same way, but it is most visible for accounts with active YouTube advertising and multiple Google Ads formats running.
When will the numbers settle after this change? Google has not given an exact timeline - it is reasonable to wait a few weeks after August 24 before treating the numbers as final.
Should we notify every client at once, or only the ones visibly affected? It is more practical to send one short heads-up to every client with an active Merchant Center account right away, even if the gap in a given account is small - it gets ahead of the question and signals the agency is tracking platform changes proactively.
Is it worth documenting this in the agency's internal knowledge base? Yes. A short note with the effective date and a link to the source saves the team from re-explaining the same discrepancy to a new hire, or when a similar client question comes up again months later.
Three Dates Worth Keeping Straight
August 24 is when the change took effect. July 1 is how far back historical data was rewritten. September 2026 is when the separate Shopping policy merger lands. Keep these distinct when briefing a client, since mixing them up makes the explanation harder to follow than the change itself.
Bottom Line
Agencies managing multiple client stores should go through every Merchant Center account this week, record a new July-August baseline, and prepare a short standard explanation for clients - the mismatch with past reports comes from Google's methodology, not from actual sales performance. Keep that explanation on file, since the same question is likely to resurface the next time someone pulls up an old report for comparison.
