Google Merchant Center Migrating from Content API to Merchant API – What You Need to Know

Today I want to talk about an important email that most merchants have recently received regarding the migration from Google’s Content API to the new Merchant API. This is a critical update that affects how your Google Shopping feeds connect to Merchant Center, and there are specific deadlines you need to be aware of.

What’s Changing?

Google is replacing the old Content API with a new system called the Merchant API. The new API comes with enhanced features and improved functionality for managing your Merchant Center account and accessing data and insights. While this is a positive change in the long run, it does require action from merchants to ensure a smooth transition.

Important Deadlines

Google has set the following migration deadlines based on your current setup:

• Beta Merchant API users: February 28, 2026
• Content API users: August 18, 2026
• Non-API users: Can migrate at any time

Don’t leave this until the last minute! I know many merchants tend to wait, but getting ahead of this will save you potential headaches down the line.

How to Check Which API You’re Using

This is crucial: don’t assume that just because you’re using a new app or even the Google & YouTube app for Shopify that you’re automatically on the new Merchant API. Here’s how to verify:

1. Log into your Google Merchant Center
2. Navigate to Settings on the left-hand side
3. Click on Data Sources
4. Scroll down to Primary Sources
5. Check the Source field

If it says “Content API,” you’re still on the old system and need to migrate. If it says “Merchant API,” you’re all set!

How to Migrate

For most merchants, especially those using the Google & YouTube app for Shopify, the migration process is straightforward:

1. Follow the instructions provided in your app
2. Or simply uninstall and reinstall the app
3. The app should automatically reconnect using the Merchant API

The Feed Label Challenge

Here’s where things get a bit tricky, and this is important for your Google Ads campaigns.

What Changes

With the old Content API, you might have had a clean feed label like “US” for your United States products. After migrating to the Merchant API, this changes to a more complex format: the currency code followed by an underscore and a random number (e.g., “GBP_123456”).

Why This Matters

If you’re targeting campaigns in Google Ads by feed label (rather than by country), this is critical. When the feed label changes, your products will become disconnected from your campaigns. You’ll need to manually reattach them in Google Ads.

Note: If you’re targeting by country instead of feed label, this won’t be as significant an issue.

Can You Change the Feed Label?

Unfortunately, no. With the old Content API, you could customize the feed label by going to the data source setup and scrolling to the bottom. However, with the Merchant API, this option is no longer available. You’ll have to work with the automatically generated feed labels.

Updating Your Google Ads Campaigns

After migrating, wait approximately 30 minutes to 24 hours, then update your Google Ads campaigns:

For Performance Max Campaigns:

1. Go to your Performance Max campaign
2. Click on Settings
3. Under Feeds, you can either:
   • Select a specific feed
   • Use all available feeds

For Standard Shopping Campaigns:

1. Click on your campaign
2. Go to Settings
3. Under Feeds, select your specific feed label

Important Considerations

Single Country Targeting: If you’re only targeting one country with your campaign, you can safely use “all available feeds” without worrying about mixing up products from different regions.

Multiple Country Targeting: If you’re targeting multiple countries, I recommend specifically assigning feed labels. While it’s rare (about 5% of cases in my experience), Google can sometimes mix things up—for example, showing products in USD when they should be in GBP. Using specific feed labels prevents this issue.

⚠️ CRITICAL UPDATE: Product ID Changes for Shopify Merchants

This is extremely important and I need to warn you about a major issue I discovered after publishing this article.

If you’re using the Google & YouTube app for Shopify and planning to migrate by uninstalling and reinstalling the app, there are two significant problems you need to be aware of:

Issue #1: Additional Markets Automatically Enabled

The new app will automatically submit feeds for all enabled markets in your Shopify store, not just your primary market.

For example, if you were only targeting the US before, but you also have Canada and European countries enabled in Shopify markets, the app will now create separate data feeds for each country. This will:

• Trigger a review process for all these additional countries
• Potentially target markets you don’t want to advertise in

Solution: Disable any markets you don’t want to target before migrating the app.

Issue #2: Product ID Format Changes (This is the BIG one!)

This is the critical issue that will significantly impact your Google Ads performance.

Old Product ID Format: Shopify_[COUNTRY-CODE]_[PARENT-ID]_[VARIANT-ID]

Example: Shopify_US_12345_67890 or Shopify_AU_12345_67890

New Product ID Format: Shopify_ZZ_[PARENT-ID]_[VARIANT-ID]

Example: Shopify_ZZ_12345_67890

The app now uses “ZZ” as a unified identifier for all markets instead of country-specific codes.

Why This is a Problem

When your product IDs change, all your historical performance data in Google Ads disappears. Google treats these as completely new products, meaning:

• All clicks, conversions, and learning data is lost
• Your campaigns essentially start from zero
• You lose all the optimization and performance history

For well-optimized accounts: Recovery may only take a few days as the account rebuilds performance data.

For slower accounts or poorly optimized feeds: You could suffer for weeks or even longer with decreased performance.

The Solution: Use Multifeed or Another Feed Management App

Unfortunately, you cannot change product IDs using Google Merchant Center’s feed rules. The product ID field cannot be modified in the primary feed (only in supplemental feeds, which doesn’t solve this problem).

The best solution is to use a feed management app such as:

• Multifeed (paid app, but worth it to preserve your data)
• Any other feed management application that supports custom product ID assignments

These apps allow you to:

• Assign your own specific product IDs
• Maintain the correct country-specific format (e.g., Shopify_GB for UK)
• Preserve all your historical performance data
• Avoid the painful restart period

What I Recommend

Before migrating the Google & YouTube app:

1. Set up a feed management solution like MultiFeed
2. Configure it to use the proper country-specific product ID format
3. Disable any unwanted markets in Shopify
4. Then proceed with the migration

If you’ve already migrated and are experiencing issues:

Don’t panic. The damage can be contained, but you’ll need to act quickly to implement a proper feed management solution.

Need Help?

I understand this migration has become more complicated than initially expected. My apologies for not catching the product ID issue in my initial article – I had known about this when the new Google & YouTube app was first introduced over a year ago, but it slipped my mind when covering the migration deadline.

If you need assistance with:

• Migrating safely without losing performance data
• Setting up MultiFeed or another feed management solution
• Recovering from a problematic migration
• Understanding which approach is best for your specific situation

🙋Questions or Need Help?
Do you have a question or need specialist support? Get in touch! I’m happy to help you optimize your Google Shopping listings for the best performance.