How can I include GTIN for some products and MPN for others? Do you have an example of how to do this within the XML file?
Hi @thais.castro.medeiro, how are you?
At VTEX, the product registration process, including the addition of identifiers such as GTIN and MPN, is done directly through the admin interface or via API. After registration, VTEX automatically generates the XML files needed for integration and data export.
How It Works:
- Product Registration:
- Registration is done directly in the VTEX admin panel or through spreadsheet or API imports. During this process, you can enter the GTIN, MPN, and other product details.
See more details at: - What is a Product?
- What is an SKU?
- What is the difference between a product and an SKU?
- Fill in SKU registration fields
- Fill in product registration fields
- Register products
- How to change the product of an SKU
- Register product specifications or fields
- Automatic XML Generation:
XML Integration
Even though the post is old, I hope this information helps you or others in the community.
Cheers,
Estevão.
This message is old, but adding to the information shared by @estevao_santos 
All of these fields should be created as new SKU specifications, configured to not appear on the product page, and sufficient to be sent along with the Product / SKU data to Google Merchant.
According to Google Merchant documentation, it is highly recommended to send the GTIN for all products that have an existing GTIN assigned by manufacturers.
The ideal scenario is to send the GTIN together with the MPN for better reach of ads approved in Google Merchant.
Note that a GTIN should only be registered if you are certain it is correct.
If an incorrect GTIN is registered, the ad may lose reach or even be disapproved. If no GTIN is provided, the MPN must be sent instead — and just like the GTIN, it cannot be made up and must follow the official industry numbering.
And if a SKU does not have these codes, the recommendation is to leave these fields blank and simply use identifier_exists as no.