Labeling Preferences
An FNSKU (Fulfillment Network Stock Keeping Unit) is a unique identifier used to track your products through Amazon's fulfillment network. When creating a shipment, you must choose who will print and apply FNSKU labels to the products: you or Amazon.
Seller Labels
With this option, you will be responsible for printing and applying labels for your products before shipping them to Amazon. You'll want to ensure you know Amazon's labeling guidelines, linked here: Use Amazon barcodes to track inventory
If your barcode preference is set to Manufacturer barcode (the default setting) in Seller Central, Amazon will require you to provide FNSKU labels for products that don't qualify to use the manufacturer's barcode. For details on using the manufacturer barcode or steps to change your barcode preference, check out Amazon's help article: Using manufacturer barcodes with FBA virtual tracking
Amazon Labels
With the FBA Label Service, Amazon prints and applies FNSKU labels to your products for a per-unit fee, currently $0.55/unit. You can enroll in this convenient service within your fulfillment settings in Seller Central.
1. Login to Seller Central.
2. In the Settings drop-down menu, click Fulfillment by Amazon.
3. In the Optional services section, click Edit.
4. Under Who labels? click Amazon to enroll in the FBA Label Service. (Clicking Merchant will cancel your enrollment.)
5. Click Update.
For more information on the FBA Label Service, check Amazon's article: FBA Label Service