How To Fix Identifier-related Errors (GTIN/MPN/Brand) on the Merchant Center

Merchant Center
Product Feed
Andrey Kisselev
April 7, 2023

Today we'll look into Identifier-related errors in Merchant Center. We'll talk about why these errors happen and how to fix them.

If you are seeing product disapprovals in your Google Merchant Center with the error description mentioning Identifier, GTIN, MPN, or Brand, this is our today's topic.

What are identifier errors and how to view them

Generally speaking, any errors in the Merchant center are not good, and you should try to fix them. Left alone, they will eventually reduce effectiveness and quality of your campaigns.

Identifier-related issues are among the most common Merchant Center issues, and by fixing them you will significantly improve health of your account.

To view the Merchant Center issues, open your Google Merchant Center, select diagnostics, click on item issues.

In the bottom part of the screen, you will see issues with the red icon. Those are product disapprovals.

Understanding the impact of identifier related errors

The first step in fixing identifier-related errors is to understand their impact on your campaign and your account.

Viewing product issues in Merchant Center
Viewing product issues in Merchant Center

To achieve that, find your identifier-related errors and look for the number in the column % of the affected past clicks. This number represents clicks on these product ads in the last 30 days.

If this number is higher than zero, it means that these products were generating traffic before they were disapproved.

Now we need to understand if that traffic also generated revenue.

Download the list of items by clicking the download icon on the far right, go to your shopping campaigns, and analyze each products' performance in the last 30 days.

Enter the correct data

The next step in addressing these issues is to enter correct data into the feed or e-commerce store.

But what data we're talking about?

Identifier attributes
Identifier attributes

These four attributes are relevant to our errors.

GTIN is the unique identifier of a product. You may know it also as a barcode. Not all products have GTIN, but when they do, it's highly recommended adding it, into your feed.

Brand is the manufacturer's brand name, not the reseller's, but the actual manufacturer's brand name.

MPN is the part number, assigned by the product manufacturer.

Identifier_exists is the tag indicating whether a product identifier exists for this product.

Rules to assign Identifiers_exists values
Rules to assign Identifiers_exists values

When it comes to assigning value to the identifier_exist, follow these three rules.

1. If you resell old or custom items without GTIN, or MPN, set identifierexists to NO (or FALSE).

2. If you resell items that have GTIN or MPN and Brand, add them to the feed and set identifierexists to YES (or TRUE), or leave this field empty. In the latter case, Google will assume that the identifierexists is YES.

3. And the most common and the most difficult situation is a product has GTIN, but you don't know it. In this case, you should set identifierexists to YES. If the items are not being used in the campaigns, the better solution would be removing them from the feed.

Fixing the incorrect value [identifier_exists] error

Let's look at the example of fixing the identifier issue Incorrect value [identifier_exists] on a Magento 2 store.

Incorrect value [identifier exists] issue
Incorrect value [identifier exists] issue

From the diagnostics view on Merchant Center, we can see that the issue has affected 17 products.

While checking the feed, we discover that the identifier exist for these product is FALSE, and the GTIN field is missing.

More info on the incorrect value [identifier exists] error
Additional information on the incorrect value [identifier exists] error

While hovering over the question mark next to the issue title, we discover a valuable piece of information: Google has detected that this item has a unique identifier, and offers two options:

  • Enter the correct GTIN
  • Remove the NO value of Identifier_exists.

Since correct GTINs are not known to us, we'll take the second route.

After changing the identifier_exist to YES, we see that disapprovals are gone, and instead warnings appeared, saying that there will be reduced performance due to missing GTIN.

While not ideal, this outcome is much better than before. At least, the products are currently not approved, and are showing in the ads.

How that was resolved on Magento 2

Supplemental feed in the Magento 2 environment
Supplemental feed in Magento 2 environment

We have resolved this issue on the Google Merchant Center level by using a supplemental feed.

The advantage of this method is that we did not have to touch the Magento 2 store.

How to create a supplemental feed

To create the supplemental feed:

1. Click Feeds in Google Merchant Center,

2. Click Add supplemental feed.

3. Enter the new supplemental feed name

4. Select Google Sheets as the way to set up your feed.

5. Next, you will be prompted to create a Google sheet

Creating supplemental feed on a Google Sheet
Creating supplemental feed on a Google Sheet

Create a sheet with two columns. One column will have IDs of the affected items.

And the second column will have identifier_exists with the desired value. In our case, it is YES.

Fetch the supplemental feed against the primary feed. The supplemental feed will overwrite the corresponding attributes in the primary feed, thus achieving our goal.

Fixing the invalid value [gtin] error

Invalid value [gtin] error on Merchant Center
Invalid value [gtin] error on Merchant Center

Another example was the invalid value [gtin]error.

In our case, fixing it was quite straightforward.

We knew that 1) the GTIN for several products was incorrect, and 2) we did not know the GTINs.

Product data flow from Magento 2 to Merchant Center, to Shopping Ads
Product data flow from Magento 2 to Merchant Center, to Shopping Ads

But because no clicks were generated from these products in the past, we could remove the products from reaching the feed. from Magento.

Since those products did not contribute to the traffic, eliminating them was the appropriate and clean solution.

Excluding Magento items from being exported to Google Ads
Excluding Magento items from being exported to Google Ads

We did it this way:

  1. in Magento, click on Catalog Feeds Profiles,
  2. Select your feed profile, edit.
  3. Select Conditions. And here are the filters that send data to the Google merchant center feed.
  4. Click on SKU does not contain.
  5. Add the SKUs of the products you need to exclude.


Fixing identifier-related errors in Merchant Center seem tricky at the first glance.

This article breaks down this task into first understanding why the errors happen, and then fixing them.

Several ways of fixing the errors in the Magento store environment are shown and explained.

Did you have any question about this topic? Ask me in the comments below.

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