Does every product need a GTIN in Merchant Center?

Definition: A Global Trade Item Number (GTIN) identifies a commercial product, and some products have none assigned. As of 17 October 2026, Google's Merchant Center documentation recommends submitting a valid manufacturer-assigned GTIN whenever one exists and allows omission for products without one.

Key facts

• Google's GTIN attribute documentation labels the attribute recommended for products with an assigned GTIN and warns that missing or incorrect values may limit visibility.
• The product identifier overview lists handmade goods, replacement parts and vintage products among examples that may lack a GTIN.
• Google's MPN attribute documentation requires a Manufacturer Part Number (MPN), an identifier within a manufacturer's range, for products without a manufacturer-assigned GTIN, with exceptions for custom-made products or products without a clearly associated MPN.
• The identifier exists attribute accepts no or false only when the product has no assigned identifiers in gtin, mpn or brand.

What happens when a product has an assigned GTIN?

Google's GTIN documentation says to submit the correct identifier for the exact product, including its color or size variant. Its examples also warn that a product with an assigned GTIN could be disapproved if it is omitted. The documented consequences therefore extend beyond the attribute's recommended label.

Under its books and media guidelines, the same page requires a GTIN for non-physical items such as digital downloads. It gives this XML attribute example:

<g:gtin>3234567890126</g:gtin>

This is Google's sample value. Each submitted product needs its own applicable identifier. The documentation requires a valid check digit and says to leave an uncertain GTIN out rather than guess a value.

What should be submitted when no GTIN exists?

Google's identifier overview permits omission for products without an assigned GTIN and directs merchants to provide brand and MPN instead. Its examples include store brands, custom-made goods and antiques. These are possible cases, so the product's actual identifiers determine the submission.

The MPN specification makes that field optional for custom-made products and products without a clearly associated MPN. Otherwise, its rule for products without a manufacturer-assigned GTIN is required. An existing MPN comes from the manufacturer.

The brand specification requires the product's brand when a brand or manufacturer is clearly associated with it. When the merchant manufactures and exclusively sells an unbranded product, Google instructs the merchant to use the store name as brand and assign an MPN. That instruction specifically replaces setting identifier_exists to false in this case. Brand is optional for products without a clearly associated brand, such as books or movies.

When is identifier_exists set to no?

A unique product identifier is product identity data submitted through gtin, mpn or brand. Google's identifier exists documentation reserves no or false for products known to have no assigned identifiers. Its XML example is:

<g:identifier_exists>no</g:identifier_exists>

The value stays in English. Google says an incorrect no or false produces a warning when evidence of an identifier exists.

The identifier overview separately addresses identifiers that exist but are unavailable to the merchant: leave the missing attribute blank. Internal store codes and identifiers from similar products are unsuitable substitutes.

Do customization, bundles or used products change the rule?

Google's GTIN guidelines retain the manufacturer's GTIN when an existing product receives engraving or other personalization. The title and description explain the customization, and is_bundle indicates it.

For a manufacturer-created bundle, the guidelines use the bundle's identifiers. For a merchant-created bundle with a main product, they use that main product's identifiers. A merchant-created multipack uses the individual product's identifiers; a manufacturer-created multipack uses the pack's identifiers.

Used and vintage products may still have a GTIN. The same guidelines say to provide the manufacturer's value if possible and set condition to used.

Related terms

• Product identifiers
• Google Merchant Center
• Product structured data
• ProductGroup structured data

FAQ

Where can I find a missing GTIN?

Google's identifier troubleshooting guidance recommends checking the packaging or contacting the manufacturer or distributor. You should leave the field blank while the correct value is unavailable.

Can I omit a GTIN because I sell the product exclusively?

The GTIN guidelines say exclusive and store-brand products may lack a GTIN. You can omit it when none is assigned; exclusivity alone does not establish that condition.

Sources

1. Google Merchant Center Help, "GTIN [gtin]", undated
2. Google Merchant Center Help, "About unique product identifiers", undated
3. Google Merchant Center Help, "MPN [mpn]", undated
4. Google Merchant Center Help, "Identifier exists [identifier_exists]", undated
5. Google Merchant Center Help, "Brand [brand]", undated

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