Missing GTIN, brand or identifier errors: how to fix them

By Kai · Updated Oct 19, 2026 · 2 min read

The identifier issues Google lists

• Missing or invalid identifiers (GTIN, MPN): examples are “GTIN not correct length” and “Invalid value (MPN)”. Assign valid, unique product identifiers.
• Custom-made items such as art or handmade goods do not need a GTIN. In Shopify, set “Custom product” to True for these items.
• Missing brand: fill in the brand (the Vendor field in Shopify). Do not use placeholders such as N/A or Generic. Makers can use their store name, and products without a brand can use the manufacturer or supplier name.
• Conflicting GTIN and brand: the GTIN must be associated with the product's brand. For US brands, verify GTIN ownership with the GS1 GEPIR tool.
• Invalid Google product category: use the numeric category ID or the full category path. The last segment alone is rejected.

A simple order of work

1. Export the affected products from Needs attention as a CSV.
2. Split them into three groups: products with a real manufacturer GTIN, custom or handmade products, and products with a brand problem.
3. Fill the real GTIN or MPN from the supplier or packaging for the first group. Never invent a number.
4. Mark custom products correctly for the second group.
5. Correct the brand field for the third group, then fix any category that is not a full path or ID.
6. Upload the corrected data and check Needs attention again after the review.

Sources

• Google Merchant Center Help: product data quality violations

Questions people ask

Keep reading

• Image too small, placeholder image or promotional overlay: how to fix
• Apparel feed attributes: size, color, gender and age group done right
• Merchant Center fix checklist: from screenshot to evidence table