GTIN, MPN and brand: what Merchant Center checks

Unique product identifiers tell Google exactly which product you sell. That lets it match your offer to the right searches, and compare it with other retailers selling the same item.

GTIN

The GTIN is the number under the barcode: UPC in North America, EAN in Europe, JAN in Japan and ISBN for books. Merchant Center validates the check digit and the prefix, so mistyped or made-up numbers get caught.

Brand and MPN

brand is expected for almost every new product. mpn, the manufacturer part number, matters when a product has no GTIN: brand and MPN together then identify it.

When a product has no GTIN

Custom, handmade, vintage and many own-brand products don't have a manufacturer GTIN. For those, set identifier_exists to no instead of leaving Google to guess.

• Every variant, such as each size or colour, has its own GTIN.
• Never reuse one GTIN across different products.
• For bundles, set is_bundle and use the GTIN of the main product.

Feedsmith never fills in GTINs, brands or MPNs for you. When they are missing, it flags them so you can take the real values from your supplier or packaging.