What it means
Identifier requirements vary by product. Brand and manufacturer part number data should describe the real item, not a guess.
How to fix it yourself
- Check the manufacturer's product record and packaging for the brand, MPN and GTIN values that genuinely apply.
- Make sure identifier values are mapped to the correct attributes in your platform or feed.
- Do not substitute internal SKU values for manufacturer identifiers unless Google's current specifications allow it for that field.
- If the item truly lacks identifiers, consult the official rules for identifier_exists and the product category.
Based on Google’s help page: support.google.com/merchants/answer/6324461. Google changes its rules from time to time, so check the issue’s own “Learn more” link in Merchant Center too.