Let me share with you a few information about this, Bauer1987.
Currently, QuickBooks Desktop only works with UPCs.
Every item has an item number associated with inventory. When printing tags from within the program using the default templates, the item number is used to create the barcode. This allows you to print and scan barcoded tags for your inventory items, whether or not they have UPC or Alternate Lookups defined.
There are several advantages when you're using the item number for the bar codes.
You can print bar-coded tags for any item in inventory and then list them on documents using a bar code scanner, even if you don't have a vendor-provided UPC code.
Item number bar codes are smaller than bar codes created from UPC or alternate lookup values, meaning they fit better on smaller tag sizes.
If a tag bar code is unscannable, it is quicker to manually enter an item number than the longer UPC or alternate-lookup