GTIN, UPC, EAN Explained: What WooCommerce Store Owners Need to Know

If you’re trying to sell on Google Shopping, you’ve probably encountered the term “GTIN” and wondered what it means. This guide explains everything WooCommerce store owners need to know about product identifiers.

What is a GTIN?

GTIN stands for Global Trade Item Number. It’s a unique identifier assigned to products for tracking and identification purposes. Think of it as a product’s fingerprint - no two products should have the same GTIN.

The GTIN system is managed by GS1, an international organization that sets standards for product identification.

Types of GTINs

GTIN is an umbrella term that includes several specific barcode formats:

Type	Digits	Common Use
UPC-A	12	North America retail
EAN-13	13	Europe and worldwide
EAN-8	8	Small products
ISBN	13	Books
ITF-14	14	Cartons/cases

UPC (Universal Product Code)

UPC is the barcode format used primarily in the United States and Canada. If you’ve ever scanned a product at a store, you’ve used a UPC.

12 digits
Starts with a number system digit (0-9)
Includes manufacturer code and product code
Ends with a check digit

Example: 012345678901

EAN (European Article Number)

EAN is the international version of UPC, used throughout Europe and most of the world.

13 digits (EAN-13) or 8 digits (EAN-8)
Compatible with UPC (a UPC can be converted to EAN by adding a leading zero)
Used globally

Example: 4006381333931

ISBN (International Standard Book Number)

ISBN is specifically for books and publications.

13 digits (ISBN-13, since 2007)
Older books may have 10-digit ISBNs
Can be used as GTIN for books

Example: 978-3-16-148410-0

Why Does Google Shopping Require GTINs?

Google requires GTINs for most products because:

Product matching - Google matches your products to their catalog for richer data
Price comparison - Users can compare prices across stores
Trust - GTINs help verify products are legitimate
Better visibility - Products with GTINs often rank higher in Shopping results

What Happens Without a GTIN?

If you don’t provide a GTIN:

Your product may not appear in Shopping results
You’ll see warnings in Google Merchant Center
Your products may be disapproved
You’ll miss price comparison features

How to Find Your Product’s GTIN

On the Product

Look for the barcode on the product packaging. The number below the barcode is typically the GTIN.

From Manufacturers

Contact your manufacturer or check their website. Many provide GTIN information in product documentation or data sheets.

Supplier Documentation

If you buy from wholesalers, GTINs are often listed in:

Product catalogs
Invoices
Data feeds

Online Databases

Search product databases:

Barcode Lookup
UPC Database
Manufacturer websites

What If Your Product Doesn’t Have a GTIN?

Some products legitimately don’t have GTINs:

Products Without GTINs

Handmade items - Custom or artisan products
Vintage items - Old products predating GTIN system
Custom products - Made-to-order items
Parts and components - Some industrial parts
Store brands - Some private label products

Using `identifier_exists = false`

For products without GTINs, you can tell Google by setting identifier_exists to false in your feed. This prevents disapprovals for missing identifiers.

Note: Products with identifier_exists = false may have lower visibility than products with valid GTINs.

Getting Your Own GTINs

If you manufacture products or need GTINs, you can purchase them from GS1:

Join GS1 in your country
Get a Company Prefix
Assign GTINs to your products

Cost: Starting around $250/year for small businesses (varies by country).

Website: www.gs1.org

Brand and MPN: The Other Identifiers

Along with GTIN, Google may require:

Brand

The product’s brand or manufacturer name. Required for most products.

Examples:

Nike
Apple
Samsung

Tips:

Use the official brand name
Be consistent across products
For unbranded products, use your store name

MPN (Manufacturer Part Number)

The manufacturer’s own identifier for the product. Useful when GTIN isn’t available.

Examples:

ABC-123
XYZ-789-BLK

When to use MPN:

Product has no GTIN
As additional identifier alongside GTIN
For parts and components

Adding GTINs to WooCommerce

WooCommerce doesn’t include GTIN fields by default. You need a plugin.

Using Google Shopping for WooCommerce

Install the Google Shopping for WooCommerce plugin (free)
Edit any product
Go to the Inventory tab
Find the GTIN, Brand, and MPN fields
Enter the values
Save

GTIN, Brand, and MPN fields in the WooCommerce Inventory tab

The fields work for both simple products and variations.

Best Practices

Be accurate - Wrong GTINs cause disapprovals
Be consistent - Use the same format across products
Include all identifiers - GTIN, Brand, and MPN when available
Verify - Double-check GTINs match the actual product

GTIN Validation

GTINs have a check digit that validates the number. Invalid GTINs will be rejected by Google.

How to Validate a GTIN

The last digit of a GTIN is a check digit calculated from the other digits. You can validate GTINs at:

Common GTIN Errors

Wrong length - UPC should be 12 digits, EAN should be 13
Invalid check digit - Number doesn’t pass validation
Incorrect format - Includes spaces or dashes
Wrong product - GTIN doesn’t match the actual product

FAQ

Q: Can I make up a GTIN?

No. GTINs must be obtained through GS1 or provided by the manufacturer. Fake GTINs will cause account suspensions.

Q: My supplier gave me a GTIN but Google says it’s invalid. Why?

The GTIN may be incorrect, or it may not exist in Google’s database. Verify with the manufacturer or check on barcodelookup.com.

Q: Do I need GTINs for variations?

Yes. Each variation (different size, color, etc.) should have its own unique GTIN.

Q: Can I use the same GTIN for multiple products?

No. Each unique product must have its own GTIN. Using the same GTIN for different products will cause issues.

Q: What if I resell products but don’t know the GTINs?

Contact the manufacturer or search the product online. Many products have GTINs listed on retailer websites or databases.

Summary

Identifier	What It Is	Required?
GTIN	Unique product number (UPC, EAN, ISBN)	Yes, for most products
Brand	Manufacturer or brand name	Yes
MPN	Manufacturer’s part number	Recommended

Key takeaways:

GTINs are required for most products on Google Shopping
Find GTINs on packaging, from manufacturers, or in databases
Use identifier_exists = false only for products that truly don’t have GTINs
Use a plugin like Google Shopping for WooCommerce to add GTIN fields

Need to add GTINs to your WooCommerce products? Google Shopping for WooCommerce adds free GTIN, Brand, and MPN fields - no paywall, no limits.