GTIN for Google Shopping

A GTIN is the product's global barcode number. UPC, EAN, JAN and ISBN are all GTINs of 8, 12, 13 or 14 digits. Google uses it to match your offer to its product catalog, which unlocks richer listings and better matching. Items that have a GTIN assigned by the manufacturer are expected to include it.

How this app fills it

• The GTIN comes from each variant's barcode field in Shopify.
• By default the app checksums every barcode and only emits values that are valid GTINs. Placeholder barcodes are silently skipped instead of causing disapprovals.
• When an item has no GTIN and no brand plus MPN pair, the app emits identifier_exists automatically so Google does not expect one.
• The Identifiers tab controls all of this, including a raw mode that emits every barcode unchecked.

Dos

• Enter real barcodes in Shopify's barcode field for every variant that has one.
• Fix invalid barcodes at the source in Shopify. The app skips them, but a real GTIN always beats none.
• Use the manufacturer's GTIN for the exact variant, not the parent product.
• Leave the barcode empty for genuine one-off products like handmade goods.

Don'ts

• Never invent a GTIN. Google validates against the GS1 registry and disapproves fakes.
• Don't reuse one barcode across different variants.
• Don't enter internal SKUs in the barcode field. SKUs belong in the SKU field and map to MPN.
• Don't buy GTINs from anywhere except GS1 or official resellers.