Incorrect identifier_exists Value in Merchant Center: Fix

What this issue means

The identifier_exists attribute is a flag. It doesn't send an identifier; it declares that none exists. Google's specification says to use no or false only when you're certain the product has no assigned unique product identifiers, and that if there is evidence an identifier exists, the product receives a warning.

Typical legitimate uses:

• Custom-made or personalized goods without a manufacturer barcode
• Handmade items sold only by the maker
• Vintage pieces, antiques and items made before GTINs existed, such as books published before 1970

Typical incorrect uses:

• Branded products you resell, like electronics, toys, cosmetics or tools
• Products you sent with a GTIN and identifier_exists set to no at the same time
• Private-label products that have a brand (your store) and could have an MPN

Text and XML feeds accept yes, true, no or false. The value must be in English.

Why it happens

• A blanket feed rule. Someone set identifier_exists = no for the entire catalog to silence missing GTIN warnings. It worked briefly, then Google started flagging branded items.
• Shopify's custom product setting was applied in bulk. In the Google & YouTube app, marking products as custom tells Google they have no GTIN or MPN. Applied to resale items, it produces this warning.
• Conflicting data. The product has a barcode in Shopify or WooCommerce, but a plugin setting or supplemental source also sends identifier_exists = false.
• Dropshipping catalogs without barcodes. The products do have GTINs; the supplier simply didn't provide them, so the store declared none exist.

How to fix it

1. Export the affected products. In Merchant Center, go to Products > Needs attention, filter for the identifier_exists issue, and download the CSV.

2. Sort products into two groups.

   • Group A, has identifiers: branded goods from manufacturers. These need the real GTIN, or brand plus MPN.
   • Group B, truly no identifiers: your own handmade, custom or vintage items. These can keep identifier_exists = no, but double-check each one.

3. For Group A, add the identifiers and remove the flag.

   • Get GTINs from the packaging or your supplier and validate them with our GTIN checker.
   • If the manufacturer never assigned a GTIN, submit brand and the manufacturer's mpn. Google requires MPN for products without a GTIN, unless they're custom-made or have no clear MPN. Don't invent MPNs or use your own SKU as the MPN for someone else's product.
   • Then either delete the identifier_exists value or set it to yes.

4. Fix it in your platform:

   • Shopify (Google & YouTube app): Open the product in the Google & YouTube channel (or use its bulk editor) and uncheck This is a custom product for resale items. Make sure the variant Barcode field holds the GTIN, and add MPN where the app asks for it. Changes sync automatically.
   • WooCommerce: In Google for WooCommerce or your feed plugin, find the identifier exists option, which may be a per-product checkbox or a global default. Turn it off for branded products and fill in GTIN, MPN and brand fields.
   • Feed rules and supplemental sources: Remove any rule that sets identifier_exists to no for every product. Replace it with a conditional rule, for example only where brand equals your own store name and gtin is empty.

5. Don't mix signals. A product should never send a GTIN and identifier_exists = no together. Search your feed export for that combination and fix it.

How long until it's fixed

Merchant Center usually reflects corrected identifiers within one to three days after the data is reprocessed. If you edited a rule, the change applies at the next fetch of the data source. Products that you mark with real GTINs may also clear related "missing identifiers" warnings in the same window.

How to prevent it

• Never use identifier_exists = no as a catalog-wide shortcut.
• Default to yes (or leave the attribute out) and only switch to no per product, with a reason.
• Add identifier collection to supplier onboarding so you're not tempted to bypass it.
• Review rules and supplemental sources whenever someone new edits the feed.

Feed shortcuts like this are among the most common problems we find in audits, and they usually cost visibility on the products that should perform best. Mercantads can review your identifier setup and correct it across your catalog through our Merchant Center service. Our feed checker is a good first look.