Can I make up a GTIN?

No. Google checks GTINs against GS1 data. Invented or reused numbers can get products disapproved. Use the manufacturer's number or set identifier_exists to no for products that genuinely have none.

Is a missing GTIN a disapproval?

Usually it shows as 'limited performance': the product can still serve but Google may show it less. Some issues and categories can still lead to disapproval, so check the status Merchant Center shows.

How many digits does a GTIN have?

Google accepts 8, 12, 13 or 14 digits: UPC (12 digits in North America), EAN (13 digits in Europe), JAN (8 or 13), ISBN-13 for books and GTIN-14 for multipacks.

Google Merchant Center: Missing value [gtin] · Limited performance due to missing value [gtin] · Missing product identifiers

Your product is missing its barcode number (GTIN)

What Google's message means

Google expects a GTIN (the number under the barcode: UPC, EAN, JAN or ISBN) for branded products that have one. This product was sent without it.

Why it matters

Without a GTIN Google can't match your item to the product catalogue, so it usually shows less often ("limited performance") and in some cases is disapproved.

Common causes on Shopify

The Barcode field on the Shopify variant is empty, so the Google & YouTube channel sends no GTIN.
Products were imported from a supplier or dropshipping app that doesn't fill in barcodes.
Only some variants have a barcode; Google checks each variant separately.
The product is your own brand or handmade and has no GTIN, but identifier_exists isn't set to no.

How to fix it

1Find the real GTIN on the packaging or ask the manufacturer/supplier. It is 8, 12, 13 or 14 digits.
2Add it to each variant in Shopify (Products → product → variant → Barcode).
3Wait for your Google sales channel to resync (usually within a day). The issue clears after Google re-processes the product.
4If the product genuinely has no GTIN (handmade, custom, or your own brand without GS1 barcodes), mark identifier_exists = no in your feed app instead. Never invent a number.

In Shopify: Shopify's Barcode field on each variant is what the Google & YouTube channel sends as the GTIN.

How to stop it coming back

Make Barcode a required field in your product-creation checklist and in supplier imports.
Ask suppliers for GTINs when you list a new branded product.
Run a weekly check for variants with an empty barcode before they reach Google.

Common questions

Can I make up a GTIN?: No. Google checks GTINs against GS1 data. Invented or reused numbers can get products disapproved. Use the manufacturer's number or set identifier_exists to no for products that genuinely have none.
Is a missing GTIN a disapproval?: Usually it shows as 'limited performance': the product can still serve but Google may show it less. Some issues and categories can still lead to disapproval, so check the status Merchant Center shows.
How many digits does a GTIN have?: Google accepts 8, 12, 13 or 14 digits: UPC (12 digits in North America), EAN (13 digits in Europe), JAN (8 or 13), ISBN-13 for books and GTIN-14 for multipacks.

Official help pages

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Google's wording and requirements change from time to time; always check the help link shown next to the issue in Merchant Center. FlagClear isn't affiliated with Google and can't guarantee review outcomes or reinstatement.