In the world of ecommerce and Google Product Listing Ads, unique product identifiers (or UPIs) matter—maybe even more than you think.

Not only do they help uniquely identify the product you are selling throughout the global marketplace but they also allow customers to easily find your product. That’s kind of a big deal when it’s so easy for a product to get lost in the shuffle of the hundreds of thousands of other products already listed online.

Product identifiers can even help Google match search queries to your listing. The more search queries you show up for, the more potential for relevant impressions and the more chances you have to convert new shoppers.

There are three common types of UPIs that Google accepts:

  • Global Trade Item Numbers (GTIN)
  • Manufacturer Part Numbers (MPN)
  • Brand

To determine which identifiers you need to provide for your products, you’ll want to check Google’s requirements.


While you may know they are required for many products on Google, many are still unfamiliar as to what a GTIN actually is and how using them can benefit ad performance.

What exactly is a GTIN?

GTIN, or Global Trade Item Number is a unique product identifier that is used to identify trade items globally.

There are different types of GTINs that vary based on product type and where the products will be sold. Google only accepts the following types of GTINs:

  • UPC: (12 digits) used in North America
  • EAN:  (13 digits) used in Europe
  • JAN: (8 or 13 digits) used in Japan
  • ISBN: (13 digits) used for books
  • ITF-14: (14 digits) used for multipacks

GTINs can usually be found on the barcode of your product's packaging. If you are selling a book, the ISBN is most likely on the book cover.

If you are unable to locate the GTIN, you can always reach out to the product’s manufacturer for the information.

Importance of Using GTINs

GTINs are especially important, as they are globally unique identifiers.

They help Google match your products to their catalog, which increases the chances of your products showing up in relevant search results, and on other Google partner sites.

Statistics show that products that are matched in Google's catalog can receive up to 40% more clicks than products that are not. Not only that, according to Google, merchants who have GTINs in their product data have seen conversion rates increase up to 20%.

Google isn’t the only channel that uses GTINs.

Adding GTINs to your product data can also help you sell more effectively on other channels like Amazon and eBay, just to name a few—and with Google Shopping leading the way, demand for GTINs is sure to grow.

In 2016, Google began enforcing stricter GTIN requirements and made them mandatory for all new products with a GTIN assigned by the manufacturer. These stricter requirements have since solidified the indentifier's importance across ecommerce platforms. 

There's no more reliable attribute to provide. After all, GTINs help Google and other platforms understand exactly what you're selling.

Check out more details on Google’s GTIN requirements.

New products with a GTIN are also required to submit the brand attribute. MPN is recommended but not required. If your product does not have an assigned GTIN, then you should submit both brand and MPN.


What is MPN?

A product's MPN is a manufacturer-assigned, unique, alphanumeric value that is used to identify a product among other products from the same manufacturer.

google shopping product identifier MPN

MPN Requirements

An MPN value is required for all products that do not have a manufacturer-assigned GTIN. Exceptions include custom made products or products that don’t have a clearly associated MPN.

That doesn’t mean you should simply leave it out if you already have GTIN values. MPNs are yet another way to help improve ad performance. 

Google states that you should use the MPN value assigned by the manufacturer as opposed to creating one yourself. In our experience, we’ve seen Google accept the MPN if it’s mapped to a non-MPN attribute such as SKU. However, following Google’s guidelines is always the preferred method.

When it comes to variations, each variant will typically have its own MPN value. An exception to this is apparel items that come in different sizes. These will likely have the same MPN value.

For additional guidelines and best practices, reference Google’s help article regarding MPNs.

Benefits of MPNs

When it comes to certain products such as electronics or tools, MPNs are key.  

Let’s take TVs for example.

For the most part, TVs are not impulse purchases. An interested shopper may first go to a brick-and-mortar store to check out various TVs. Then with various models in mind, they may compare those with other relevant models online. Finally, with an ideal model in mind, they may use the unit's MPN to search for the exact TV they're interested in.

If you include this information in your listing, your ad is sure to surface over a competitor's ad that is lacking the relevant MPN.

Home products and auto parts are other categories where MPN is commonly referenced.

Adding relevant UPIs to your ads, such as MPNs, can help increase the discoverability of your ads and can potentially improve ad performance.


google shopping product identifier Brand

What is Brand

A product's brand attribute is simply its brand name.

Brand Requirements

This globally referenced UPI is required by Google for all products that have a clear brand name.

Products that don’t have a clear brand assigned to them such as custom made goods, books or movies may leave out the brand attribute. In these cases, Google says to leave the brand attribute blank—don't add a non-brand value (like "N/A" or "Generic") for these items.

If what you're selling is ever missing both a GTIN and brand or a MPN and brand, then you would set the identifier_exists attribute to "no." This lets Google know that a product doesn't have those product identifiers.

If you are selling a product that comes in different sizes and/or colors, the brand attribute should remain the same for the different variants.

Final Thoughts

Before selling on Google, you should familiarize yourself with the unique product identifiers that are available for your items and see if they match up with Google’s requirements.

UPIs help Google understand exactly what you're selling, and as a result, directly affect ad performance.

Not all products have GTINs, MPNs, and/or a brand, but you'll want to provide what you have, and make sure that your product really doesn't have one of those UPIs before leaving a field blank.

You want to be as accurate as possible when submitting this information. If you submit your products without using correct identifiers, or submit incorrect information, you’ll likely run into Merchant Center errors that will prevent your products from going live.