How to Update or Add a UPC to an individual product in Shopify
In Shopify click on Products in the left navigation then the individual product you want to add a UPC to.
Scroll to the Inventory section
Add the UPC and click Save at the bottom of the page
How to bulk add the UPC to your Products in Shopify using a csv file
You can bulk update your products in Shopify using the instructions on the Shopify site:
