Global Trade Identifier Numbers are an important factor in the performance of your Google Shopping campaign. Read on for why they matter so much, and how you can solve some of the most common errors.
Global Trade Identifier Numbers (GTINs) are numbers uniquely identify your products. Some common examples of GTINs include:
- UPC
- EAN
- JAN
- ISBN
Google uses these numbers to jump start your advertising, leveraging patterns and signals from when the same product has been offered by you or other advertiser. Why re-learn what has already been learned, after all?
So, generally speaking, this means that if a GTIN exists for your product, you should include it in your product data feed. Failure to do so will result in your ads underperforming.
Google Merchant Center has a number of different errors and warnings it reports for missing or invalid GTINs. Here is what they mean:
| Error | Description | More Info |
| Incorrect value [identifier exists] | You have told Google that no GTIN exists, but Google believes otherwise. You will need to either supply a GTIN, or request a review. | Google Help |
| Invalid value [gtin] |
GTINs have formatting requirements. This error indicates that the GTIN you have supplied does not meet these requirements. Here are some things to check:
|
Google Help |
| Incorrect value [gtin] |
Google believes that the GTIN that you have submitted is not the right GTIN for your product. |
Google Help |
| Unsupported coupon value [gtin] |
You have submitted a GTIN that is a range reserved for coupons. These start with the prefixes 98, 99, and 05. |
Google Help |
| Unsupported bulk value [gtin] |
You have submitted a GTIN that is in a range reserved for bulk sales of a product. These start with a prefix 9. |
Google Help |
| GTIN not related to brand |
The GTIN that you have submitted does not match up with the brand that you have submitted. |
Google Help |
What if my product doesn't have a GTIN?
Many products don't have a GTIN, particularly if you manufacture them yourself. In this case, you can submit a brand and a manufacturer part number (or MPN) instead. MPNs do not have to be globally unique. But there are still a couple of checks that Google performs that may result in errors.
| Error | Description | More Info |
| Incorrect product identifier [mpn] | Google believe that the MPN you have submitted does not match up with the other product data you have supplied. | Google Help |
| Invalid value [mpn] | Only use MPNs that have been assigned by the manufacturer rather than a reseller or a distributor. Also ensure that the corresponding brand name is correctly submitted via the brand [brand] attribute. If the product doesn’t have an MPN, clear the current value and leave the field blank. | Google Help |
To change the GTIN or MPN for any product, the best thing to do is to update them on your website. However, you can also edit them directly in FeedOps by using the Product Level Optimizations feature.