Why does the Merchant Center report “Item identifier missing” even though a GTIN is entered?

Merchant Center reports a missing item identifier despite a GTIN mostly because the GTIN does not arrive in the gtin attribute, because Google rejects it as invalid, or because brand and MPN are missing. Only the value that ends up in the attribute after processing counts. A GTIN in the description, in an unmapped column or with a wrong check digit is treated as not provided.

For branded products, Google recommends submitting all three unique product identifiers together: GTIN, brand and MPN. According to Google, products that have a GTIN but are submitted without one may have limited visibility, and incorrect identifiers can lead to disapproval.

Why does Google not recognise the GTIN?

• Wrong column or mapping. If the feed column is called “EAN” or “Barcode” and is not mapped to the gtin attribute, Merchant Center receives no GTIN. The same happens when a shop plugin stores the EAN in a custom field that the export does not include.
• Invalid value. Google checks the GTIN against GS1 rules. A wrong check digit, an unsupported length or a value from a restricted range (prefixes 02, 04 or 2) or a coupon range (05, 98 or 99) is rejected.
• Internal numbers instead of a GTIN. Your own article numbers in the gtin field are not GTINs. Google explicitly says not to guess, make up or copy values from similar products.
• Brand or MPN missing. The message often refers to the combination. A product with a GTIN but no brand, or with a brand but neither GTIN nor MPN, can still be flagged.
• identifier_exists set wrongly. If the attribute is set to no or false for products that do have identifiers, Google issues a warning. A blanket setting for the whole feed is a common cause.
• Duplicate GTIN. Several products with the same GTIN and the same variant attributes (for example colour or size) for the same country and language are not allowed. Each variant has its own GTIN.

How do I find the cause step by step?

1. Open the issue in Merchant Center. List the affected products and read the exact message. Missing, invalid, incorrect and restricted GTINs are separate issues with different fixes.
2. Check the processed value. Open an affected product and look at the value that actually arrived in the gtin attribute. If the field is empty, the problem is the export or the mapping, not the GTIN itself.
3. Check the raw data. In your feed file, shop export or API request, check that the column or element is named exactly gtin. In XML feeds that is <g:gtin>.
4. Test check digit and length. Google accepts 8, 12, 13 or 14 digits. Check samples with the GS1 check digit calculator. Spaces and dashes are accepted but ignored.
5. Add brand and MPN. Submit all three identifiers for branded goods wherever you have them.

What about products that really have no GTIN?

One-of-a-kind items, custom-made goods, antiques or products made before GTINs existed often have none. For these, set identifier_exists to no or false (the value must be in English) and leave GTIN, brand and MPN empty if none of them exist. Use this only for products where you are certain no identifier has been assigned, and set it per product, not for the whole feed.

More background on rejected products is in our article on products being rejected in Merchant Center.

First check which value arrives in the gtin attribute after processing. If it is empty, fix the export or mapping. If it is there, check the check digit, the number range and the combination with brand and MPN.

Sources

• Merchant Center Help: GTIN [gtin]
• Merchant Center Help: About unique product identifiers
• Merchant Center Help: Identifier exists [identifier_exists]

Is Merchant Center still flagging missing identifiers? We check your feed, shop export and mappings and make sure GTIN, brand and MPN arrive correctly. Book a free intro call or read more about our Google Ads and Shopping management.