Product IDs can be reused, including:
- UPC
- EAN
- ISBN
- ITF
- Non-categorized Product ID
If you need to create a new product ID for your product, you can use the Check Digit Calculator in order to ensure that your UPC is valid.
SKUs cannot be reused - all SKUs must be unique.
Reusing SKUs results in product creation issues, as well as fulfillment confusion.