Product feeds · Practical answers
Missing GTIN on a handmade product: what should Merchant Center receive?
Distinguish a genuinely unassigned identifier from an identifier missing in your feed.
Do not invent a GTIN or automatically mark every handmade-looking product as having no identifiers. Establish what identifiers the actual product has, then follow Google’s requirements for that product and its identifier_exists value.
Missing in the feed is not the same as nonexistent
Google’s identifier guidance recognizes that some custom, one-of-a-kind, or older products may lack assigned unique product identifiers. It also explains that an incorrect “identifier exists” value can cause an issue when Google believes a valid identifier exists.
The practical question is about the product itself, not whether the store has filled in a barcode field. A reseller and the maker of an original custom item may be in different situations.
Investigate one affected item
- Identify the exact item and variant flagged in Merchant Center.
- Check manufacturer or supplier records for legitimate identifiers.
- Review the submitted GTIN, brand, MPN, and identifier_exists fields together.
- Compare the actual product with the description and landing page.
- Correct the authoritative product source before requesting the available review.
Do not copy an unrelated product’s identifier to clear a warning. A passing-looking feed field is not useful if it describes the wrong item.
Why similar items may have different outcomes
In an illustrative clothing store, an original made-to-order design and a branded base garment resold unchanged should not automatically inherit identical identifier assumptions. Record what is being sold and where the product information came from.
Likewise, a product family can include both standard and customized offers. A blanket rule applied to the entire catalog can turn an isolated omission into a wider data-quality problem.
Keep the correction reproducible
Write down the identifier decision, the supplier evidence, the field mapping, and the affected scope. If an integration overwrites Merchant Center edits, fix the upstream mapping instead of repeatedly applying a temporary patch.
After the data updates, check the product’s current status rather than assuming that submitting a value means approval. Review outcomes depend on the actual offer and platform requirements.
EP4P manages feed quality alongside Shopping strategy. Product data is part of the advertising work, not an administrative task left disconnected from campaign results.
Sources and further reading
References checked November 9, 2026. Platform settings and policies change; check the documentation that applies to your account.
Discussion inspiration: Reddit PPC question: GTIN on a custom product. Community discussions help identify questions; the technical answer is checked separately.
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