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

Why Identifier-related errors happen in Merchant Center and how to fix them.

Andrey Kisselev
Andrey Kisselev

Table of Contents

If you are seeing product disapprovals in your Google Merchant Center with the error description mentioning Identifier, GTIN, MPN, or Brand, this is 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 the 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 the health of your account.

Get the Print Version

Tired of scrolling? Download a PDF version for easier offline reading!

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

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

    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

    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 the correct data into the feed or e-commerce store.

    But what data we're talking about?

    Identifier attributes in the product feed

    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 to add it to 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

    Follow these rules when assigning value to the identifier_exist:

    1. If you resell old or custom items without GTIN, or MPN, set identifier_exists to NO (or FALSE).
    2. If you resell items that have GTIN or MPN and Brand, add them to the feed and set identifier_exists to YES (or TRUE), or leave this field empty. In the latter case, Google will assume that the identifier)_exists 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, set identifier_exists to YES. If the items are not being used in the campaigns, the better solution would be to remove 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 as viewed in Merchant Center

    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_exists for these products is FALSE, and the GTIN field is missing.

    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

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

    The advantage of this method is that the original data on Magento 2 store was not touched.

    How to create a supplemental feed

    To create a 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 in the Google Sheet

    6. 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

    7. Fetch the supplemental feed against the primary feed

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

    Fixing the invalid value [gtin] error

    Invalid value [gtin] error viewed in 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. Correct GTINs were not known to us

    But because no clicks were generated from these products in the past, we had decided to block the products from reaching the feed. from Magento.

    How product data flows from Magento store to Merchant Center to Shopping Ads

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

    Blocking Magento items from getting to Google Ads

    That's how we did it in Magento:

    1. 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
    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.

    Understanding why the errors happen makes it easier to fix them.

    merchant center

    Andrey Kisselev Twitter

    Shopping ads specialist, founder @ Addi Marketing. LinkedIn

    Andrey Kisselev Twitter

    Shopping ads specialist, founder @ Addi Marketing. LinkedIn