Limited Performance Due to Missing Identifiers: What Google Merchant Center Sellers Should Fix

Quick Answer

Products without complete identifiers appear less frequently and in lower ad positions. Add your GTIN (from the product barcode), brand name, and MPN to your feed to restore full matching and improve performance.

What This Issue Means

Google uses product identifiers to match your listings to what shoppers are searching for. Without complete identifiers, Google cannot reliably match your product to search queries, resulting in fewer impressions, lower click-through rates, and reduced overall ad performance.

Why It Happens

• GTIN is missing or incorrect, preventing accurate product matching
• Brand name is generic, missing, or does not match Google's brand database
• MPN is missing, leaving the product without a unique variant identifier
• identifier_exists was not set correctly for products without standard GTINs
• GTINs were added but are tied to the wrong product variant
• Brand authorization was not established for the products being sold
• Inconsistent identifier formats across product variants in the feed
• Feed updates were not submitted after identifiers were corrected on the website

What to Check First

• Check which products in Merchant Center show limited performance due to missing identifiers
• Verify the GTIN on each product's physical item or packaging
• Confirm the brand name is the official manufacturer brand
• Find the MPN for each product variant from the manufacturer
• Check if identifier_exists needs to be set to no for products without standard GTINs
• Verify the GTIN, brand, and MPN are consistent across all variants of the same product
• Ensure the corrected feed is submitted and the changes have propagated

Evidence to Prepare

• Screenshot of Merchant Center performance report showing limited impressions for flagged products
• Screenshot of the feed identifier fields showing which are empty or incorrect
• Photo of product barcodes with GTIN for each flagged product
• Supplier invoice showing the official GTIN, brand, and MPN for each product
• Screenshot of corrected feed data after adding all identifiers

Step-by-Step Recovery Path

1. Run a product diagnostics report in Merchant Center to find all products with missing identifiers
2. Collect the correct GTIN, brand, and MPN for each affected product
3. For products without standard GTINs, set identifier_exists to no and provide brand and MPN
4. Update your product feed with the complete and correct identifier values
5. Submit the updated feed and wait for Google to re-process the product data
6. Monitor your Shopping campaign performance to confirm improvement
7. If performance does not improve, check for remaining identifier inconsistencies

Mistakes to Avoid

• Adding a placeholder GTIN like 00000000000000 to avoid the error
• Using a brand name that is not the official manufacturer brand
• Assuming that adding identifiers once will permanently fix performance issues
• Not checking if your GTIN is registered to the correct product variant
• Submitting feed updates without verifying the changes were received by Merchant Center