Error:
- Missing Product fields Missing required field: UPC



Resolution:

As outlined, Walmart would accept four different types of product identifiers, which would be unique for every item and at least one of them is required in order to list on that channel. Single and also multiple identifiers would accepted and see this Walmart guide and also the details below:

- GTIN (14 digits)
- UPC (12 digits)
- ISBN (10 or 13 digits)
- ISSN (8 digits)

Other identifiers like Manufacturer Part Number / MPN or Model Number cannot be used as Product IDs, but they can be used for the Item Specifics, since those example identifiers are recommended and not required.