Fixing missing GTINs in Google Merchant Center on Shopify

A GTIN is the number under a product's barcode. In Australia it's usually 13 digits (an EAN). Google uses it to recognise that your product is the same item other stores sell, which is why Merchant Center keeps asking for it.

When Google wants a GTIN

Google's Merchant Center help says:

• A GTIN is recommended for every product that has one assigned by the manufacturer.
• Products with a missing or incorrect GTIN may have limited visibility.
• Only provide a GTIN if you're sure it's correct.
• Some products don't have a GTIN, and then you don't need to submit one.

So the rule of thumb: if the product came from a manufacturer with a barcode on the box, give Google that number. If it didn't, don't make one up.

Where the GTIN goes in Shopify

1. In your Shopify admin, open the product.
2. Open each variant. In the inventory section, put the barcode number in the Barcode field.
3. Save, and repeat for every variant: each size or colour usually has its own barcode.

For a lot of products, export your products to CSV, fill the barcode column, and import it again. Do a test with two or three products first.

If you make your own products

Google covers this case directly:

• For your own brand or private-label products without a manufacturer barcode, skip the GTIN and give Google your brand and an MPN (your own part or style number) instead.
• For one-off or custom-made items, leave the GTIN blank.

If you want barcodes for your own range, for example to sell through retailers, GS1 Australia is the organisation that issues them. Google's page says GTINs should follow the official GS1 rules, so numbers from anywhere else can cause problems.

Make sure it reaches your product pages too

Merchant Center isn't the only place the GTIN matters. Google's guide to product structured data recommends including all applicable GTINs in the page's product data, and calls the most specific GTIN “the most accurate representation of the product.” Many Shopify themes add the barcode to the page data automatically once the Barcode field is filled. Our inspection checks whether it got there.

The AI shopping angle

AI shopping assistants have the same problem Google has: working out that the item on your site is the item a shopper asked about. A barcode is the cleanest way to say so. We check whether it's readable. Whether that changes what an assistant recommends isn't proven yet, by us or anyone.