An Amazon FNSKU barcode identifies FBA units associated with a seller’s offer. If your stock requires Amazon barcode labels, print them through Seller Central and apply one to each sellable unit before sending the shipment. A readable label helps the fulfilment centre receive the unit against the right inventory.
The FNSKU is not the product’s ASIN, your own seller SKU or the manufacturer’s barcode. Knowing which identifier Amazon expects for your shipment helps you avoid stock being delayed or received incorrectly.
What is an FNSKU?
An FNSKU is an Amazon inventory identifier used for FBA. When a unit is prepared with an Amazon barcode, the barcode links it to the relevant product and seller inventory. This helps Amazon distinguish your units from another seller’s units of the same product during fulfilment-centre handling.
Check the barcode requirement shown for your offer and shipment in Seller Central rather than assuming every product needs an FNSKU sticker. Barcode eligibility and preparation instructions can depend on the item and the inventory settings available to you.
FNSKU vs ASIN, seller SKU and manufacturer barcode
These identifiers serve different purposes:
| Identifier | What it identifies | What to remember for FBA |
|---|---|---|
| ASIN | A product in Amazon’s catalogue | Sellers offering the same catalogue product can share an ASIN. It does not, by itself, identify whose FBA unit is being received. |
| Seller SKU | Your own inventory listing or offer in Seller Central | You use it to organise your inventory. It is not automatically the barcode a fulfilment centre should scan on the physical unit. |
| Manufacturer barcode (EAN or UPC) | A product identifier printed by the manufacturer | Amazon may allow eligible stock to be tracked using this barcode rather than an applied Amazon barcode. |
| FNSKU / Amazon barcode | FBA inventory associated with a seller’s offer | If Seller Central calls for an Amazon barcode, the correct label needs to be scannable on each sellable unit. |
For example, identical products offered by different sellers may have the same ASIN and manufacturer barcode. An Amazon barcode provides a way to identify which seller’s inventory a labelled unit belongs to. The name printed under a barcode is less useful than checking that the label generated in Seller Central matches the stock you are preparing.
Amazon barcode or manufacturer barcode?
The practical choice is whether your product is eligible to use its existing manufacturer barcode or needs an Amazon barcode applied to each unit. A manufacturer barcode can reduce labelling work where Seller Central permits its use. An Amazon barcode makes the seller-inventory association explicit on the unit, but adds a printing and application step.
Do not choose based only on whether the packaging already has an EAN or UPC. Review the barcode option and preparation instructions for the specific offer in Seller Central before you buy labels, ask a supplier to label stock or confirm a shipment. If you want Amazon to apply labels to eligible units, check the available labelling service and its fee there as well.
That decision belongs alongside your other preparation costs. You can explore seller tools and use the fee calculator when planning the cost of sending stock to FBA. Account for any supplier or third-party labelling work separately when assessing your margins.
How to find and print FNSKU labels in Seller Central
The exact screens can change, so follow the current prompts in Seller Central. In general, the workflow is:
- Open the FBA offer you intend to replenish and start creating a shipment or sending inventory.
- Confirm the product, seller SKU, unit quantities and preparation details. Check whether Seller Central specifies an Amazon barcode or allows a manufacturer barcode.
- If you are responsible for Amazon barcode labelling, use the label-printing option offered during the shipment workflow to download or print the unit labels.
- Check the labels against your shipment plan before printing the full batch. Keep labels for different products or variations separate.
- Apply labels to the sellable units, then complete the remaining shipment and box-preparation steps shown in Seller Central.
If a supplier or preparation service handles the work, send them the labels generated for the correct offer and clear instructions about which units receive them. Do not substitute an ASIN, a seller SKU printed from another system or a label from a previous product without checking it against the current shipment.
For the wider dispatch process, see how to send products to Amazon FBA.
How to apply labels so they scan
Put one correct Amazon barcode label on each sellable unit that requires it. Place it on a flat, accessible surface of the unit’s final packaging. It should be firmly attached, legible and free from folds, seams, tape glare or other obstructions that could prevent a scan.
Cover other scannable product barcodes on that unit where the Amazon barcode is intended to be scanned instead. Check all sides of the packaging for an exposed EAN, UPC or duplicate barcode. Do not put a unit label only on the shipping carton: carton labels and product-unit labels do different jobs. If the sellable unit is wrapped or bagged, make sure the correct barcode remains visible and scannable on the outside of the final prepared unit.
Barcode placement is only part of preparation. Review the Amazon FBA packaging requirements for UK sellers and follow the current product-specific instructions in Seller Central.
Common mistakes that disrupt receiving
- The wrong FNSKU on a unit. Labels mixed between products or variations can cause scans to point to the wrong inventory.
- An uncovered manufacturer barcode. More than one scannable product barcode can create ambiguity about which identifier should be read.
- A label that cannot be scanned. Creases, curved edges, smudged printing or tape over the barcode can make identification difficult.
- A label hidden inside packaging. Staff need to scan the unit as it arrives prepared, without opening its sellable packaging to find the barcode.
- Labelling only the outer box. A carton label does not identify each individual unit when the box is opened for receiving.
- Assuming an old shipment’s settings still apply. Check the current offer and shipment instructions before preparing a new batch.
Before dispatch, inspect a sample from every labelled product and variation, then confirm that the remaining units follow the same preparation. Seller Central is the place to check current barcode, labelling and shipment requirements for your stock.