Do resellers have to put an FNSKU label on every unit now?
Max VershininFounder of Arbitrage Herofnskuamazon fbafba labelingcomminglingonline arbitrage
Ask AI to summarize this article:
Yes. Since March 31, 2026, Amazon's FBA Barcode Choice and Labeling FAQ requires every reseller who is not the brand's Brand Representative to put an Amazon barcode, the FNSKU label, on every unit sent to FBA. The rule applies even when the product already has a UPC or EAN barcode. The FNSKU code Amazon assigns to your offer is what its warehouses scan instead. Units that were already in Amazon's fulfillment centers before March 31 keep selling as they are.
This guide brings Amazon's barcode, SKU and prep rules together for resellers. It also shows how a label cost changes the profit of a unit, because Amazon has stopped its paid prep and labeling service in the US and in its European stores.
The FNSKU code Amazon assigns identifies your units, and a UPC identifies the product
An FNSKU is the barcode Amazon creates for one seller's offer of one product. Amazon's FAQ calls these Amazon barcodes "X00 labels". You print it in Seller Central and stick it on each unit.
A UPC or EAN is the manufacturer's barcode. It is the same on every unit of the product, whoever sells it. The ASIN is Amazon's number for the product page. Our glossary explains what a UPC or EAN barcode is.
For example, two resellers send the same blender with the same UPC. Each reseller gets a different FNSKU for that blender. Amazon scans the FNSKU and knows whose unit it holds and whose unit it ships.
Amazon ended commingling for inventory shipped on or after March 31, 2026
Amazon stopped commingling for all inventory shipped to its fulfillment centers on or after March 31, 2026. It announced the change in a Seller Central forum post titled "Commingling practices will end effective March 31, 2026".
Amazon defines commingling as fulfilling an order "using exact product matches from the closest available inventory, even if that inventory belonged to a different seller". In the past, a reseller could send units with only the manufacturer barcode, and Amazon pooled them with other sellers' units of the same product. Amazon's reason for the change is that "most sellers maintain inventory levels that keep products close to customers", so fast delivery works without the pool.
The change also affects your buyers. Amazon's FBA Barcode Choice and Labeling FAQ says that customers who buy from you "will only receive products from your inventory, including returns and removals".
Who can still send inventory without an FNSKU label
Only a brand owner can still send stickerless inventory. Amazon's FAQ sets three conditions: the seller has the Brand Representative role for that brand in Amazon Brand Registry, the unit is in new condition, and it has one scannable UPC, EAN or ISBN that matches one ASIN. Every other case needs an Amazon barcode on every unit. That includes a brand owner's product with a GTIN exemption, because the FAQ allows stickerless inventory only for products with a valid GTIN.
| Seller and product | Amazon barcode on every unit? |
|---|---|
| Reseller, product with a UPC or EAN | Yes |
| Authorized reseller of the brand | Yes |
| Brand Representative, new product with one matching UPC, EAN or ISBN | No, the manufacturer barcode is allowed |
| Brand Representative, product with a GTIN exemption | Yes |
| Any seller, product without a manufacturer barcode | Yes |
The diagram shows the same rule as the table. An online arbitrage seller buys from retail stores and is not the brand owner, so every unit needs the label. The same is true for a wholesale buyer, even with a letter of authorization from the brand.
How to switch an existing SKU to Amazon barcodes
A reseller whose SKU still uses the manufacturer barcode creates a new SKU for the same ASIN, with Amazon barcode as its barcode type. Amazon's help page "Create a new SKU to switch to Amazon barcode" gives these steps:
- In Seller Central, open Inventory, then Manage All Inventory.
- Search for the ASIN or the SKU.
- Open the three-dot menu next to it and select Add another condition.
- Enter a new seller SKU, complete the required fields and save. The item condition can stay the same.
- On the Convert to Fulfillment by Amazon page, select Amazon barcode as the Barcode Type.
- Add dangerous goods information if Amazon asks for it, then click List as FBA.
Sellers on the Professional plan can do the same in bulk. They set the FBA Product Barcode Preference to Amazon barcode, then upload the new SKUs with a listing template.
The new SKU keeps the product's ratings and reviews, because Amazon measures them per ASIN. Sponsored Products ads, coupons, deals and Subscribe & Save do not move to the new SKU automatically, and the new SKU gets its own inventory recommendations. To avoid confusion, Amazon suggests closing the old SKU's offer and placing a removal order for its units.
What an FNSKU label must look like
An FNSKU label must be a scannable, black-on-white label between 1 x 2 inches and 2 x 3 inches, placed flat over the other visible barcodes on the unit, except serial number and Transparency codes. Amazon's help page "Use Amazon barcodes for FBA" lists these Amazon FBA labeling requirements:
- The label shows the ASIN or FNSKU, the product name and the item condition.
- The barcode has white space of 0.25 inch on each side and 0.125 inch above and below it.
- It is printed with black ink on white, non-reflective labels with removable adhesive.
- It comes from a thermal or a laser printer with at least 300 dots per inch. Inkjet printers are not allowed.
- It is not placed on a curve or a corner, and it sits at least 0.25 inch from the edge of the packaging.
- Each item in a case pack has its own label, and any barcode on the case is removed.
- It stays readable and scannable for 24 months.
You print labels in the Send to Amazon workflow with Print SKU labels, or from Manage Inventory with Print item labels. For laser printers, Seller Central supports sheets such as 30 labels per page of 1 x 2 5/8 inches on US letter paper, and several A4 sizes.
What labeling costs a reseller per unit in 2026
An FNSKU label now costs a reseller either their own time or a prep center's fee, because Amazon no longer sells a labeling service. Amazon still tries to correct a unit that arrives without a label, but it counts that unit as defective, and a unit labeled wrongly is not eligible for reimbursement.
Amazon no longer labels units for a fee
Amazon's FBA Prep Service page says it stopped offering prep and item labeling in the US store on January 1, 2026. Until then, it charged $0.55 per unit for labeling. Amazon's UK FBA Prep Service page says Amazon stopped prep and labelling in its European stores on July 1, 2026.
One published prep center price is higher than Amazon's old fee. The US prep center Ecom Circles lists FNSKU labeling alone at $1.00 per unit on its price page, read on October 15, 2026. Its prep clients also need a plan of $97 a month or more.
What a label cost does to one example unit
A label cost has the largest effect on products with a low profit per unit. Our article on every FBA fee that hits a small seller in 2026 uses one example unit: a large standard-size product just under a pound, sold at $25. A 15 % referral fee of $3.75 and the fulfillment fee of $4.60 for January 15 to October 14, 2026 take $8.35 and leave $16.65. The fulfillment fee is higher from October 15, 2026 to January 14, 2027, so the same example then leaves less.
The table adds an example buy price of $10. ROI here is profit ÷ buy price. The example leaves out inbound shipping, the prep center's monthly plan and any other costs. On this unit, a $1.00 label lowers the ROI by 10 percentage points.
| Label cost per unit | Share of the $16.65 | Profit before other costs | ROI |
|---|---|---|---|
| None | 0 % | $6.65 | 66.5 % |
| $0.55, Amazon's former fee | 3.3 % | $6.10 | 61.0 % |
| $1.00, one prep center's price | 6.0 % | $5.65 | 56.5 % |
With Amazon's fees for January 15 to October 14, 2026, this $25 example with a $10 buy price leaves $6.65 of profit without a label cost, an ROI of 66.5 %. Amazon's former $0.55 fee would take 3.3 % of the $16.65 and leave $6.10, an ROI of 61.0 %. Ecom Circles' $1.00 per unit takes 6.0 % and leaves $5.65, an ROI of 56.5 %. All three figures are before inbound shipping, the prep center's monthly plan and other costs.
The $25 unit is an example, not advice: check Amazon's current fees and your own costs before you buy stock. You can enter your own label cost in the "Other costs" field of the free FBA profit calculator. The calculator divides profit by the buy price plus shipping and other costs, so its ROI is a little lower than the table.
What to do next
Before your next FBA shipment, confirm your brand role, set the right barcode type and plan the labeling.
- Check your role for each brand you sell in Seller Central's Brand Relationships page. Without the Brand Representative role, plan an FNSKU label on every unit.
- Before your next shipment, create a new SKU with Amazon barcode as the barcode type for every offer that still uses the manufacturer barcode.
- Choose how you label: a thermal or laser printer at home, or what an FBA prep center does for a fee per unit.
- Add the label cost per unit before you buy, and check that the product still meets your profit target.
- Leave time for labeling in your shipping plan. It matters most before the cut-off for when to stop sending stock into Q4.
- After your first labeled shipments, check the Inbound Performance Dashboard for labeling defects.
Can an authorized reseller still send stickerless inventory?
No, an authorized reseller of a brand must also put an Amazon barcode on every unit. Amazon's FAQ says that as of March 31, 2026, "all resellers, including authorized resellers, must use Amazon barcodes" when they send inventory to its fulfillment centers. A letter of authorization does not change this. Amazon allows the manufacturer barcode only when the seller has the Brand Representative role for the brand, the product is new, and one scannable UPC, EAN or ISBN matches one ASIN.
What happens to units that arrive at Amazon without an FNSKU label?
Amazon treats a reseller's unit that arrives without an Amazon barcode as defective. Amazon's FAQ says it will try to correct the label and report the defect on the Inbound Performance Dashboard. Units that are not labeled correctly are not eligible for reimbursement if they are lost or damaged. Amazon's barcode page adds that wrong label placement can delay processing and may lead to unplanned prep service fees.
What happens to stickerless stock that was already in Amazon's warehouses?
Stickerless units that were in transit to or stored in Amazon's fulfillment centers before March 31, 2026 need no action. Amazon's FAQ says they keep selling under their original SKUs, and only new shipments must use Amazon barcodes. During the change, Amazon waives the low-inventory-level fee at the FNSKU level for affected ASINs in its US, Canada, Germany, France, Italy and Spain stores.
Does the new FNSKU rule apply to Amazon UK sellers?
Yes, the UK version of Amazon's FBA Barcode Choice and Labelling FAQ on Seller Central UK gives the same March 31, 2026 rule for resellers. The UK is not in the list of stores where Amazon waives the low-inventory-level fee during the change. Amazon's UK help page also says that prep and labelling services in its European stores ended on July 1, 2026.
Keep reading
Four related guides cover the barcode terms, the shipment steps and the other FBA costs of a unit.
- What a UPC or EAN barcode is: the manufacturer barcode that the FNSKU label now covers.
- Every FBA fee that hits a small seller in 2026: the other per-unit costs behind the example above.
- How to start online arbitrage and send your first FBA shipment: the workflow in which you now print labels.
- The free FBA profit calculator: add your label cost and see the profit per unit.