There are many different types of barcode values that can be set for products on Amazon. To help ensure that Shiptheory downloads the most preferable type of barcode from your Amazon products, you can set an order of preference for Shiptheory to check and download barcode values.
How to change Product Barcode download preference
Go to your Amazon Central settings in Shiptheory and in the bottom left click on the grey Advanced Settings icon. Scroll down to the Product Barcode Type Preference setting where there are listed a number of barcode types. These can be click-and-dragged into the order of your choosing in which Shiptheory will look for a barcode value to download from each product.
In the image below, Shiptheory will look for an EAN value first and download that if it exists. If not it will move on to checking for a UPC, and so on...
If you have any other questions, just get in contact with the Shiptheory support team!