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FNSKU

Also known as: Fulfillment Network Stock Keeping Unit, Amazon barcode, X-code

Amazon's Fulfillment Network Stock Keeping Unit, a seller-specific barcode that identifies one seller's units of a product inside Amazon's fulfillment network.

Amazon generates the FNSKU (usually starting with "X") for each FBA listing; it differs from your own seller SKU and from the product's UPC or EAN. Because it is tied to your seller account, it keeps your inventory separate from other sellers' units of the same product. You download and print the labels from Seller Central.

Since January 1, 2026, Amazon no longer offers item labeling for FBA shipments in the US, so units must arrive already labeled. Many importers send the FNSKU PDF to the Chinese factory or a prep center and check the labels in the pre-shipment inspection. See shipping from China to Amazon FBA.

Related terms

FBA (Fulfillment by Amazon)GS1 barcodePrep center

Guides that use this term

Shipping

Shipping from China to Amazon FBA: Rules, Options and Pitfalls

How to ship inventory from China into Amazon FBA in the US: carton and pallet limits, labels, importer of record, DDP forwarders, AGL and prep centers.

Updated 2026-09-20 · 6 min read

Part of Amazon FBA & Dropshipping.

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