Since 31 March 2026, Amazon has required every unit that a reseller sends into Fulfilment by Amazon (FBA) to carry its own Amazon-issued FNSKU barcode, even when the product already carries a manufacturer barcode such as a GTIN, UPC or EAN. If you sell on Amazon as a reseller, this changes how you prepare your stock. In this blog we explain what the requirement means, and how to meet it.
What Is an FNSKU, and Why Have the Rules Changed?
FNSKU stands for Fulfilment Network Stock Keeping Unit. A manufacturer barcode identifies what a product is. An FNSKU goes further by also identifying which seller it belongs to.
Amazon no longer holds identical items from different sellers together in the same inventory. Labelling every unit means Amazon can trace each individual item, which makes it easier to prevent counterfeit and non-compliant goods being sold, to attribute defects and returns to the right seller, and to give customers more confidence in what they are ordering.
The requirement only applies to resellers. If you are a brand owner enrolled in Amazon Brand Registry, you can continue to use your manufacturer barcodes without applying an extra label.
What Your FNSKU Label Must Show
Every label needs to carry four things:
• Your Amazon-issued barcode
• The product’s ASIN or FNSKU
• The product name
• The item condition
Amazon also requires clear white space, both around the barcode and between the label content and the edges of the label: 6.35mm at the sides, and 3.18mm at the top and bottom. Without that margin, the barcode may fail to scan.
Amazon FNSKU Label Sizes and Materials
Amazon barcodes must be printed in black on white, non-reflective labels. Each label must measure between 25.4 x 50.8mm and 50.8 x 76.2mm. The barcode format is CODE128. The minimum barcode height is 6.35mm and there must be a clear “quiet zone” of 2.5mm or greater each side of the barcode.
If you print from a laser printer, Amazon generates a PDF built to a fixed A4 grid. Your label sheet has to match one of those layouts, or the barcodes will not line up with the die-cut labels.
The supported A4 layouts are:
• 21 labels per sheet: 63.5 x 38.1mm. These are very common for FNSKU because the height allows comfortable barcode placement and readable text. These are our LL21 Labels or our EL21 Labels.
• 24 labels per sheet: 63.5 x 33.9mm, 63.5 x 38.1mm, 64.6 x 33.8mm, 66.0 x 33.9mm, 70.0 x 36.0mm or 70.0 x 37.0mm. These are slightly wider, so are useful when product titles are longer or when you want more horizontal space for scannability. We sell these as our LL24 Labels, our EL24 Labels, or our EL24S Labels.
• 27 labels per sheet: 63.5 x 29.6mm. These give you more labels per sheet. They are good for small items but ensure your barcode height remains ≥6.35 mm as required.
• 40 labels per sheet: 52.5 x 29.7mm. These are a compact format. They work for small packaging but may be tight for long product names.
• 44 labels per sheet: 48.5 x 25.4mm. These are very small so are only suitable when products are tiny and text can be abbreviated. You must take care that you still meet Amazon’s minimum barcode size (25.4mm x 12.7mm). We sell these on request, do contact us for details.
Printing Your FNSKU Labels
You can print labels from the Send to Amazon workflow, or at any time from Manage Inventory. In Manage Inventory, select your products, choose Print item labels from the group actions menu, then choose your paper or sticker type.
The tools in your seller account are optimised for thermal printers, laser printers are also supported. Do not use an inkjet printer. Every label has to stay readable and scannable for 24 months, and inkjet print is prone to smudging and fading. Use a printer with a resolution of 300 dots per inch (dpi) or higher and set your printer scaling to None or 100% so that the PDF is not resized.
Alternatively, if you do not want to print the labels yourself, you could ask your supplier to label your products for you, or Amazon will do it, for a fee.
Applying Your Labels Correctly
Place the label on a flat area of the packaging, never on a curve, corner or seam, and allow 6mm between the edge of the label and the edge of the packaging. Cover any other visible barcodes so that they cannot be scanned by mistake, with the exception of serial number barcodes and Transparency authentication codes, which do need to be readable to Amazon.
Take particular care with food, drink and supplements. Your label must not cover any information required under the Food Information Regulations. That includes the legal product name, the ingredients list, allergen information, the Quantitative Ingredient Declaration, net quantity, best before or use by dates, storage conditions, country of origin and the nutrition declaration.
What Happens If You Get It Wrong?
A product that arrives at a fulfilment centre without a required barcode is marked as defective. Amazon applies a label itself and charges you an unplanned prep fee, and the defect is reported on your Inbound Performance Dashboard. Repeated non-compliance can lead to inventory being refused, returned or disposed of, and to future shipments being blocked altogether.
The problems Amazon reports most often are missing barcodes, units labelled with a barcode that does not match the product, and barcodes that will not scan because they are smudged, placed around a curve, or printed onto a reflective surface.
Amazon FNSKU Labels from Forms Plus
If you are labelling units yourself, your label stock has to match one of Amazon’s layouts.
We hold a range of A4 die-cut laser label sheets and thermal labels that are suitable:
• LL21 Die-Cut Laser Labels: 21 labels per A4 sheet at 63.5 x 38.1mm, matching Amazon’s 21-up layout, with a selvedge stripon the top, bottom and each side.
• LL24 Die-Cut Laser Labels: 24 labels per A4 sheet at 63.5 x 33.9mm, matching Amazon’s 24-up layout, also with a surrounding selvedge strip.
• EL21 Labels: 21 labels per A4 sheet at 70mm x 42.5mm, matching Amazon’s 21-up layout, but taking up the full sheet of paper, with no selvedge strip.
• EL24 Labels: 24 labels per A4 sheet at 70mm x 37.3mm, matching Amazon’s 24-up layout, but taking up the full sheet of paper, with no selvedge strip.
• EL24S Labels: 24 labels per A4 sheet at 70mm x 35mm, matching Amazon’s 24-up layout, but taking up the full sheet of paper, with a selvedge strip top and bottom.
• Direct Thermal Labels 2″ x 1″: Thermal labels for use in direct thermal printers, that measure 50mm x 25mm and meet the FNSKU label requirements.
• 44 labels per A4 sheet: these are available on request, contact our team for details.
All are supplied on FSC-certified label stock and tested for feed reliability through standard office laser printers. These labels are high tack, but peelable options are also available, contact us for details.
Forms Plus have been supporting businesses with their printing and packaging requirements for over 45 years. If you are not sure which format you need or have any other questions about Amazon labels, do Contact Our Team. If you need a label size we do not hold, our Bespoke Label Service can produce it to your specification.
For full information on the new FNSKU labelling requirement, visit Amazon Seller Central or watch this video from Amazon.