TABLE OF CONTENTS
Update/Add a UPC/EAN or ISBN 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.
Update/Add a UPC/EAN or ISBN in Shopify - Bulk
You can bulk update your products in Shopify using the instructions on the Shopify site:
You can check GTIN/UPC existence here https://www.gs1.org/services/verified-by-gs1