How to Fix "Missing or Invalid GTIN" in Google Merchant Center

What is a GTIN and why does Google care?

GTIN (Global Trade Item Number) is a unique product identifier assigned by manufacturers. It includes EAN-13 (Europe), UPC-A (North America), ISBN-13 (books), and JAN (Japan). Google uses GTINs to match your products with its product catalog, enabling richer product listings and better auction performance.

Products with valid GTINs get priority in Shopping auctions. Google has stated this explicitly — GTINs help them understand exactly what you’re selling, which improves ad relevance and often leads to lower CPCs.

When is GTIN required?

• Required: For all products that have a manufacturer-assigned GTIN (most branded products)

• Not required: Custom-made products, vintage items, handmade goods, store-brand products without a GTIN

• If your product genuinely has no GTIN: set identifier_exists to no

Common GTIN errors

Error: “Missing GTIN”

You haven’t provided a GTIN for a product that Google believes should have one (based on the brand and category).

Fix: Find the GTIN from your supplier, manufacturer, or the product packaging (barcode number). Add it to your feed.

Error: “Invalid GTIN — unsupported format”

The GTIN you provided doesn’t pass validation. Common causes:

• Wrong length — GTIN must be 8, 12, 13, or 14 digits

• Invalid check digit — The last digit is a checksum calculated from all other digits. Wrong check digit = invalid GTIN.

• Restricted prefix — GTINs starting with 02 or 04 are internal/store-use codes, not valid for Google Shopping.

• Using SKU instead of GTIN — Your internal SKU is not a GTIN. These are different identifiers.

Error: “Incorrect GTIN”

The GTIN you provided is valid format but doesn’t match the product. Google cross-references GTINs with manufacturer databases.

Fix: Verify the GTIN matches the exact product variant (color, size). Different variants have different GTINs.

How to find GTINs for your products

• Product packaging — The barcode number on the box IS the GTIN (EAN/UPC)

• Manufacturer/supplier — Request a product data sheet with GTINs

• GS1 databases — Search gepir.gs1.org for registered GTINs

• For your own products — Register with your local GS1 organization to get your own GTIN prefix

What if you genuinely don’t have a GTIN?

For custom, handmade, or unbranded products:

• Set identifier_exists to no in your feed

• Provide brand + mpn (manufacturer part number) as alternative identifiers

• If neither exists, identifier_exists: no alone is sufficient — but expect lower auction priority

GTIN validation checklist

• Exactly 8, 12, 13, or 14 digits (no letters, no spaces, no dashes)

• Check digit is correct (use an online GTIN validator)

• Doesn’t start with 02 or 04

• Matches the specific product variant, not the parent product

• Matches what’s in GS1/manufacturer databases