FNSKU label or shipping label? They are not the same thing
Worth settling first, because arriving at the wrong one costs you a sheet of stickers.
An FNSKU label identifies a unit inside Amazon’s warehouse. It goes on the product — one per unit — and carries the FNSKU code as a barcode with the product name underneath. You print these many-up on an A4 sticker sheet, peel and apply before the shipment goes to the fulfilment centre. That is what this page makes.
A shipping label identifies a parcel in transit. It goes on the outside of the box, one per parcel, carrying the customer address and the AWB barcode. If that is what you need, use the Amazon label crop tool instead.
Why FBA needs the FNSKU at all
Amazon commingles inventory by default — your unit and another seller’s identical unit sit in the same bin. The FNSKU is what makes yours yours. A missing or unreadable FNSKU means the unit cannot be received, and a shipment of unlabelled stock either gets refused or gets charged an FBA labelling fee per unit.
So the label is not paperwork. It is the difference between inventory that arrives and inventory that sits in a problem queue.
Label size and sheet layout
Amazon publishes a size range for FBA product labels, and the practical answer for most sellers is an off-the-shelf A4 sticker sheet.
The common sheets are 65-up (38.1 × 21.2 mm) and 24-up (63.5 × 33.9 mm). The 65-up is cheap and fits a lot per sheet, but a long FNSKU plus a product name gets cramped — check the bar width warning before printing a hundred. The 24-up is more comfortable and what to use if your product names are long.
Two things to get right. Leave the quiet zone — barcodes need clear space either side, so do not fill the sticker edge to edge. And keep the human-readable text underneath; warehouse staff use it when a scan fails, and Amazon expects it.
The tool below shows the bar width in millimetres as you change label size. Anything under 0.25 mm is marginal on a thermal printer, and it will tell you so rather than letting you find out at the fulfilment centre.
Getting your FNSKU list out of Seller Central
FNSKUs are assigned per product per account, so they have to come from your own Seller Central rather than being derived from the ASIN.
They appear in your inventory report, and in the label-printing flow when you create an FBA shipment. Export the report, take the FNSKU column, and paste it here — one per line, with an optional product name after a comma so the label carries a caption a human can read.
One caution worth stating plainly: an FNSKU is not a barcode you can invent. Unlike an internal SKU, it is issued by Amazon and tied to your listing. Generating a plausible-looking code produces stickers that scan as nothing at the warehouse.
If you want internal stock codes rather than FBA labels, the SKU generator makes those, and the bulk barcode generator puts them on a sheet.
Printing so the warehouse can read them
The same rule as every barcode on this site, and it is worth repeating because it is the one people skip.
Print at 100%, never “fit to page”. Scaling a sticker sheet even a few per cent shifts every label off its die-cut and narrows the bars. You end up with a sheet where the barcodes straddle the cut lines.
Use a laser printer if you have one. Inkjet on sticker paper smudges under a scanner and in a warm warehouse. If inkjet is what you have, let the sheet dry fully before handling it.
Test one sheet before running a hundred. Print a single page, scan a label with a phone barcode app, and check the code that comes back matches. Thirty seconds against a wasted box of stickers.
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Frequently Asked Questions
What is an FNSKU label?
A product label that identifies your unit inside Amazon’s warehouse. It goes on the item itself, one per unit, carrying the FNSKU as a barcode with the product name underneath. It is not the shipping label that goes on the parcel — that is a different tool.
Can I generate my own FNSKU code?
No. Unlike an internal SKU, an FNSKU is issued by Amazon and tied to your listing, so it has to come from your Seller Central inventory report or the FBA shipment flow. A plausible-looking invented code produces stickers that scan as nothing at the warehouse.
What size should an FNSKU label be?
An off-the-shelf A4 sticker sheet is what most sellers use — either 65-up at 38.1 × 21.2 mm or 24-up at 63.5 × 33.9 mm. The 65-up is cheaper per label but gets cramped with a long code and product name. The tool warns you when the bars become too narrow to print reliably.
What happens if my FNSKU label will not scan?
The unit cannot be received into inventory. In practice the shipment either sits in a problem queue or Amazon applies its own label and charges a per-unit labelling fee. Both are more expensive than reprinting a sheet, which is why testing one sheet first is worth the thirty seconds.
Do I need the text under the barcode?
Yes, keep it. Warehouse staff read it when a scan fails, and Amazon expects the human-readable code on the label. The tool prints it by default and there is no good reason to switch it off.
Is this the same as a shipping label?
No. A shipping label goes on the outside of the parcel and carries the customer address and AWB barcode, one per parcel. An FNSKU goes on the product, one per unit, and never leaves the warehouse. For shipping labels use the Amazon label crop tool.
FNSKUs come from your Seller Central, not from this page. This puts codes you already have onto a printable sheet with real Code 128 barcodes. Test one sheet with a phone scanner before printing a hundred.