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Why does Merchant Center say "Limited performance due to missing value [gtin]" for my Shopify products?

Short answer

Google couldn't find a GTIN (a UPC, EAN or ISBN barcode number) for these products. The warning doesn't remove the product from Google Shopping, but Google can't reliably match it to the catalog, so it may be shown less. If the manufacturer assigned a barcode, enter it in the product's Barcode field in Shopify; if the product has none (your own brand, custom or handmade), don't make one up.

What a GTIN is

A GTIN is the number under a product's barcode: UPC in North America (12 digits), EAN in Europe (13), ISBN for books, and ITF-14 on cases. Valid lengths are 8, 12, 13 or 14 digits. Google uses it to recognise which product you sell and to group your offer with other sellers of the same item.

Is it an error or a warning?

It is a warning. Google lists GTIN as recommended, not required, for products that have a manufacturer-assigned one. The product stays eligible, but it may get limited visibility. It becomes a real problem when the value is wrong: a GTIN with a bad check digit, a restricted prefix (02, 04 or 2, used for in-store numbers) or a coupon range (05, 98, 99) can get the product disapproved.

Where Shopify keeps it

In the Shopify admin, open the product. The Barcode (ISBN, UPC, GTIN, etc.) field is under Inventory, per variant. Each variant (each size and colour) has its own GTIN; one number copied onto every variant is wrong.

How to fix it on Shopify

  1. Find the barcode on the packaging, in your supplier's price list, or in the file from your distributor.
  2. For a few products, type it into the Barcode field on each variant.
  3. For many, use Products → Export (CSV). Fill the Variant Barcodes column and import the file back with "Overwrite products with matching handles" ticked. Or select products and use Bulk edit, adding the Barcode column.
  4. The Google & YouTube channel sends the change on its next sync. Merchant Center re-checks the product within a few days.

When the product has no GTIN

Own-brand, private-label, custom-made, handmade and vintage goods usually have no GTIN, and you don't need to buy one to sell on Google. Make sure the product has a correct brand (Shopify's Vendor field) and, if you have one, an MPN (manufacturer part number). Never enter a made-up or reused number: an invalid GTIN is worse than none.

Questions

Will adding GTINs make my products show more?

Google says products without a GTIN may have limited visibility. Adding the correct one removes that limit; it doesn't guarantee more impressions.

Can I buy GTINs from a reseller?

Google validates GTINs against GS1. Numbers that aren't registered to your company through GS1 can be rejected. For your own brand, register with GS1 or leave the field empty.

Related guides

Sources

Last reviewed 30 September 2026