If you sell a product, you probably need GS1-128 labels. The GS1-128 includes your company prefix code, along with other information that identifies the carton contents. Buy a GS1 Company Prefix that will accommodate the number of UPCs you need for your products. Remember that the length of your prefix will affect the cost — a shorter prefix is more expensive because it allows you to generate more UPCs. Your GS1 Company Prefix will also be used as part of the number that will be on your GS1-128 labels, which you adhere to your cartons and pallets as required by the retailer.