You opened Merchant Center this morning and half your feed is flagged for missing GTINs. The dashboard makes it sound like every product needs one. It does not. The rule is narrower than the warning suggests, and merchants who understand the actual boundary stop guessing and start fixing the right rows.
What you'll take away
- Not universal — GTINs are required only when a manufacturer-assigned identifier genuinely exists for the product.
- Two distinct gaps — Missing data you forgot to add is different from data that was never created, and Google treats them differently.
- Use the signal — Set identifier_exists to false for products with no GTIN rather than fabricating a value.
- Pair the fields — Brand and MPN together can satisfy identifier requirements for products without a GTIN.
- Category matters — Google's product data specification ties GTIN requirements to product category and condition.
A GTIN is a manufacturer-assigned number that uniquely identifies a product in the global supply chain. The most common form is a UPC or EAN barcode, and it travels with the product from factory to shelf. Google Merchant Center uses it to match your listing against a known catalog entry and serve the correct product to the right shopper.
Do all products in Google Merchant Center need a GTIN?
No. Google requires a GTIN only for products that have been assigned one by the manufacturer and fall into categories where identifiers are required. For custom goods, vintage items, handmade products, and private-label items without a manufacturer barcode, no GTIN exists to submit. The distinction that matters is between information you have not added yet and information that does not exist.
The field tells Google what to expect
The identifier_exists attribute accepts true or false. Set it to true when the product has a manufacturer identifier, even if you have not located it yet. Set it to false when the product genuinely has no manufacturer-assigned identifier. This single field controls how Google evaluates the rest of your identifier data.
Think of the identifier_exists field as a declaration on a customs form. When you check "true," you are telling the officer that the product has paperwork somewhere and you will produce it. When you check "false," you are stating that no paperwork exists for this item because of what it is. Checking "true" and then handing over nothing gets you held up. Checking "false" when the product actually does have paperwork is fraud.
Google's product data specification lists roughly 50 product categories where GTINs are required for new condition items. Apparel and clothing have softer requirements. Electronics and media tend to be strict. The category you assign affects whether Google enforces the GTIN or merely recommends it.
What happens if you submit a fake or placeholder GTIN?
Google will disapprove the item. The value is checked against issued identifier databases, and a fabricated number fails validation. Merchants sometimes paste a repeated string like 0000000000000 or borrow a GTIN from a different product to clear the warning. Both approaches trigger disapproval and can affect the health of the entire feed.
From the trenches — A merchant selling custom engraved cutting boards pasted the same UPC across 200 products to silence a missing-GTIN warning. Google disapproved every one of them within 48 hours. The fix was setting identifier_exists to false for each item, which cleared the warnings and restored approval for the full catalog.
The cost of a bad identifier is not just one disapproved product. Feed-level issues can suppress impressions across items that are otherwise compliant, and repeated policy violations can lead to account-level suspension. A placeholder that looks harmless on a Tuesday can become a suspension case by Friday.
When is brand and MPN enough instead of a GTIN?
For products without a GTIN, Google accepts brand and manufacturer part number (MPN) as a substitute identifier pair in many categories. MPN is the alphanumeric code a manufacturer uses to distinguish a specific product variant. Submitting both gives Google enough information to disambiguate your listing from similar products in the auction.
| Product type | GTIN required | What to submit instead |
|---|---|---|
| Branded electronics | Yes | GTIN, brand, MPN |
| Private-label apparel | No | Brand, MPN if available |
| Handmade or custom goods | No | identifier_exists = false, brand |
| Vintage or used items | No | identifier_exists = false, brand |
| Bundle or kit | Depends | GTIN if the bundle has one, otherwise brand and component MPNs |
Not every product has an MPN. If you manufacture your own goods, you may not assign part numbers at all. In that case, submit your brand and set identifier_exists to false. Google will not penalize you for the absence of a value that was never created.
How do you find the correct GTIN for a product?
The GTIN is printed on the product packaging as a barcode and is often available on the manufacturer's website or in the invoice from your supplier. For products you source through a distributor, the distributor's catalog or EDI feed typically includes the UPC or EAN. The most reliable source is the product packaging itself.
Finding and verifying a GTIN
Google's product data specification allows up to 50 GTINs per item for product variants like color or size. Each variant should carry its own unique identifier. Submitting the same GTIN across multiple variant rows causes Google to treat them as duplicates, which suppresses all but one listing from the auction.
Before · one GTIN for all variants
gtin: 0081000205123 (shared across red, blue, and green)
After · unique GTIN per variant
gtin: 0081000205123 (red), 0081000205124 (blue), 0081000205125 (green)
Variant identifiers must be unique
Two shirts in different colors are two products. Each needs its own GTIN, not a shared one. A shared identifier tells Google the listings are duplicates, and only one survives in the auction.
Which products are exempt from the GTIN requirement?
Google's specification exempts several product types from the GTIN requirement entirely. Custom goods made to order, handmade items sold through platforms like Etsy, vintage and antique items, one-of-a-kind products, and some licensed merchandise do not carry manufacturer barcodes. These products should have identifier_exists set to false.
The exemption is not a loophole. It is a recognition that not every product enters the supply chain with a global identifier. A hand-thrown ceramic mug does not have a UPC. A 1960s vintage lamp was manufactured before the UPC system existed. Forcing a GTIN onto these products would mean inventing one, which is the worst thing you can do.
The safest feed strategy is to audit your catalog by product type. For each item, answer one question: did a manufacturer assign a global identifier to this product? If yes, find it and submit it. If no, mark identifier_exists as false and move on. The audit is faster than chasing disapprovals.
Common questions
Is a GTIN required for all Google Shopping products?
No. Google requires a GTIN only when the manufacturer has assigned one and the product category enforces identifiers. Products without a manufacturer-assigned identifier, such as handmade or custom goods, should set identifier_exists to false. Fabricating a value triggers disapproval and can affect the entire feed.
What does identifier_exists false mean in Google Merchant Center?
Setting identifier_exists to false tells Google Merchant Center that the product has no manufacturer-assigned identifier, no GTIN, and no MPN. This is appropriate for handmade, custom, vintage, or private-label products. Google will not penalize the listing for missing identifiers when this field is set accurately.
Can I use MPN instead of GTIN in my product feed?
Yes, in many categories. When a product does not have a GTIN, Google accepts brand and MPN as a substitute identifier pair. MPN is the manufacturer's own part number for the product. If the product has neither a GTIN nor an MPN, set identifier_exists to false rather than leaving the fields blank.
What happens if I submit a wrong or fake GTIN?
Google validates submitted GTINs against issued identifier databases. A fake or mismatched GTIN will cause the product to be disapproved. Repeated identifier violations can suppress impressions across the feed and may lead to account-level review. Always verify the check digit and confirm the identifier matches the exact product variant before submitting.
Do apparel products need a GTIN in Google Shopping?
Apparel has softer GTIN requirements than categories like electronics or media. Google recommends but does not always require a GTIN for clothing. Brand is required for apparel, and MPN should be submitted when available. Each variant, such as a different color or size, should have its own unique identifier if the manufacturer assigned them.