# Incorrect value: identifier exists The "Incorrect value [identifier_exists]" issue means the feed declared that a product has no GTIN, MPN or brand, but Google has evidence that it does. On Shopify it usually follows a blanket identifier_exists=no rule, applied to every product with an empty barcode, catching branded goods that really have a GTIN. - **Canonical URL:** https://www.feedlab.io/knowledge/errors/incorrect-value-identifier-exists - **Last reviewed:** 3 November 2026 - **Source:** feedlab knowledge base - **Licence:** free to quote and cite with attribution to feedlab ## How this appears in your account - `Incorrect value [identifier_exists]` - `Incorrect value: identifier exists [identifier_exists]` - `Incorrect value: identifier exists (US visibility limited)` ## Why it happens on Shopify ### identifier_exists was set to no across the catalogue A common shortcut for silencing missing GTIN warnings is a feed rule that sets identifier_exists to no everywhere, or wherever the barcode is empty. Branded products that do have a GTIN are then declared as having none. ### The barcode is empty in Shopify but the product has one The variant barcode field is optional, so it is often blank for goods bought from a manufacturer that printed a GTIN on the packaging. Google can recognise the same product from other merchants' offers and knows an identifier exists. ### A Merchant Center rule overrides the Shopify data Feed rules or a supplemental feed set up in Merchant Center to clear an earlier warning keep applying long after the catalogue changes. Products added later inherit the no declaration even when their barcodes are filled in. ### The feed sends a GTIN and identifier_exists=no together Some feeds set identifier_exists from one rule and gtin from another. When both fire, the row both supplies a GTIN and claims none exists, which is contradictory. ## How to fix it 1. **List the affected products and check their packaging data** — Download the affected items and confirm with the supplier or the physical product whether a manufacturer GTIN exists. If the product is resold from a brand, the answer is almost always yes. 2. **Add the real GTIN to the Shopify variant barcode** — Fill the barcode field on each variant with the manufacturer's GTIN, per size and colour. Do not invent or buy numbers to fill the gap; only the GTIN the manufacturer assigned matches the product. 3. **Remove identifier_exists=no from these products** — Either set identifier_exists to yes or stop sending the attribute for products that have identifiers. The rule should only fire for products that genuinely have none. 4. **Narrow the rule to genuine cases** — Limit identifier_exists=no to custom, handmade, vintage, made-to-order and similar goods, identified by vendor, product type or tag rather than by an empty barcode. An empty barcode tells you about your data, not about the product. 5. **Supply brand and mpn where there is no GTIN** — For branded products that have a manufacturer part number but no GTIN, send brand and mpn and leave identifier_exists alone. Declaring no identifiers is only correct when none of the three exist. ## How feedlab handles this feedlab treats identifier_exists as a conditional rule rather than a global switch, so it can be set to no only for vendors, product types or tags you mark as unbranded, and never on a row that also carries a valid GTIN. The rule preview shows exactly which products receive the declaration against your real catalogue before the feed is published. ## Frequently asked questions ### How does Google know my product has a GTIN? Google states that products incorrectly set to no while there is evidence a unique product identifier exists will receive a warning. Google does not spell out what that evidence is, but branded products are widely sold by other merchants with their GTIN, so a no declaration on them stands out. ### When is identifier_exists=no the right value? Only when the product has no GTIN, no MPN and no brand assigned by a manufacturer: custom goods, handmade items, one-off vintage pieces and similar. Google recommends setting it only when you are certain no identifiers exist. ### I do not know the GTIN. What should I do instead? Ask the supplier or check the packaging, because the barcode printed on retail goods is the GTIN. Until you have it, sending brand and mpn is more accurate than declaring that no identifiers exist. ## Primary sources - [Google: identifier_exists attribute specification](https://support.google.com/merchants/answer/6324478) - [Google: Unique product identifiers](https://support.google.com/merchants/answer/160161)