FBA uses barcodes to identify and track inventory throughout the fulfillment process. Each item you send to an Amazon fulfillment center requires a barcode.
There are two kinds of barcodes for identifying products:
Amazon will always use the manufacturer barcode to track inventory throughout the fulfillment process, unless you change your barcode setting. If more than one seller has inventory with the same manufacturer barcode, Amazon fulfills orders with inventory that’s closest to the customer. We do this to facilitate faster delivery.
If you do not have an eligible barcode for your product, an Amazon barcode can be used in place of the manufacturer barcode.
For more information, see Using the manufacturer barcode to track inventory.
Amazon barcodes must be applied to all products that are not tracked using manufacturer barcodes. This category is comprised of:
You can print Amazon barcodes and apply them to your products yourself, or Amazon can print and apply them for a per-item fee. For more information, see Use an Amazon barcode to track inventory and FBA Label Service.