UPC And EAN Barcodes Requirements For Zappos and 6pm.com Vendors UPC And EAN Barcodes must be GS1 Certified when conducting business with Zappos and 6pm.com. Vendors should place a human-readable and scannable UPC label (12 digits) or EAN label (13 digits) on every individual product packaging sent to the FC. Only one UPC or one EAN should be … Read More →