When the Merchant Center reports ‘Item identifier missing’ even though a GTIN is entered, this is often due to formatting errors or incorrect attribute assignments. Basically, Google uses the GTIN to uniquely identify products. Therefore, correct entry is crucial for ad delivery. Additionally, a valid GTIN improves visibility in Shopping.

Why does the Merchant Center report Item identifier missing despite GTIN?

The Merchant Center does not recognize a GTIN if it is in the wrong attribute field or has an invalid format. Furthermore, GTINs must contain the correct check digit, otherwise they are rejected as invalid. However, Google also accepts alternative identifiers like MPN and brand when no GTIN exists. Check whether your products are being rejected for other reasons.

How to fix the Item identifier missing error

Enter the GTIN in the correct attribute field ‘gtin’ and make sure it contains 8, 12, 13, or 14 digits. Therefore, you should validate the check digit before uploading. Additionally, spaces and special characters must be removed. More information is available in the Google help on GTIN.

Our recommendation

Implement automatic GTIN validation in your feed creation process. Basically, you should calculate and verify the check digit of every GTIN before uploading. Furthermore, we recommend setting the identifier_exists attribute to ‘false’ for private-label products without a GTIN and providing MPN and brand instead. Additionally, regular diagnostics checks help detect new GTIN errors early.

Conclusion

Missing or incorrect GTINs are a common rejection reason in the Merchant Center that can be easily avoided through correct formatting. However, validation requires technical setup. Our Google Ads agency ensures your product identifiers are always correct.