The 31 March 2026 FBA barcode change, and what it costs you
Amazon is ending stickerless commingled inventory. For resellers that means an FNSKU label on every single unit sent to FBA — a new per-unit cost, a new step on the bench, and a decision to make about the stock you have already sent in.
The short answer
From 31 March 2026 Amazon stops running stickerless commingled inventory. If you are a reseller who is not enrolled in Brand Registry as a brand representative for the product, every unit you send into FBA needs an Amazon-issued FNSKU label on it — even when the item already carries a perfectly good EAN, UPC or GTIN.
Brand owners go the other way. If you are the registered brand representative, Amazon can track your units against the manufacturer barcode virtually, and you are no longer obliged to sticker them.
What is actually changing
Commingling is the arrangement where Amazon treated identical units from different sellers as interchangeable. You sent in ten units of an EAN, a customer bought yours, and Amazon shipped whichever unit of that EAN was closest to the buyer — possibly somebody else's.
It made fulfilment cheaper, and it made counterfeits and condition disputes very hard to pin on anyone. Ending it means every unit in a fulfilment centre has to be traceable to the seller who sent it, and the mechanism for that is a unit-level barcode belonging to your account.
Does it apply to you?
| Your position on the product | From 31 March 2026 |
|---|---|
| Reseller — wholesale, arbitrage, distribution | Label every unit with your FNSKU before it goes in a box |
| Brand owner, enrolled as brand representative | No sticker required — units track against the manufacturer barcode |
| Private label without Brand Registry | Treated as a reseller — label every unit |
| Anything you already sell as labelled stock | No change. You were already doing this |
The people this actually hits are UK wholesale and arbitrage sellers who have been sending in manufacturer-barcoded stock untouched. If that is you, an operation that used to be open the case, count, box it now has a labelling step in the middle of it, on every unit, permanently.
What an FNSKU is, and where you get one
An FNSKU is Amazon's own barcode for one product from one seller. Where an EAN says "this is a 400g jar of coffee", an FNSKU says "this is a 400g jar of coffee that you sent in". It looks like X001ABCDEF and Amazon issues it against your SKU once the offer exists.
You do not invent one. It comes back from Amazon after the listing is there, which is why labelling and listing are really the same problem: a unit you cannot label is usually a unit you have not created an offer for yet.
What to do before the deadline
- Decide which side you are on, brand by brand. If you own a brand and are not in Brand Registry, that enrolment is now worth real money in avoided labour.
- Price the labour in. A label, a printer and a person is a per-unit cost. On thin wholesale lines it decides whether the buy is worth making, so it belongs in your cost of goods before the next order, not after it.
- Sort out printing. A thermal label printer is the difference between an evening and a weekend. A4 sheets of 21 or 24 work but stop being tolerable past a few hundred units.
- Check your prep partner. If a 3PL preps for you, get it in writing that they are labelling every unit from March, and what they charge per unit to do it.
- Look at the stock already in Amazon's warehouses. That is the part nobody plans for — see below.
The part people miss: stock already in a fulfilment centre
The change is about how units are identified and tracked, so inventory you sent in months ago under the old arrangement is the awkward case. Check what Amazon says about your existing commingled units well before the date rather than after it, and plan for a removal order if the answer is that they cannot stay as they are.
It is a much cheaper problem in January than in April, when every other seller is asking the same question and removal and prep capacity is the bottleneck.
What happens if you send unlabelled stock anyway
Units arriving without the unit-level identification Amazon now expects get flagged rather than received cleanly. In practice: stock that is physically in the building but not sellable, a case to open, and either a prep fee to have Amazon fix it or a removal order to get it back.
None of those are catastrophic on their own. All of them are worse in Q4.
How this looks in Eve SellerOps
Workflows builds inbound shipments on Amazon's own Fulfillment Inbound API, so the barcode requirement it shows you is the one Amazon returns for that item rather than a rule of thumb we hardcoded. Items needing your own label are identified while the stock is still on the bench, and FNSKU labels come out as a PDF ready for a label printer.
If a unit has no offer yet, Scout resolves its barcode to the right ASIN and creates the listing — which is what makes the FNSKU exist in the first place. Both are on the free plan.
Common questions
Do I need to relabel stock I have already sent to Amazon?
Possibly, and it is the question to settle first because every option is slow. Check the status of your existing commingled units in Seller Central well before the deadline. If they cannot remain as they are, the path is a removal order, relabelling and a fresh inbound shipment — weeks, not days, if you leave it late.
Does Brand Registry get me out of labelling entirely?
For products where you are the enrolled brand representative, yes — Amazon tracks those units against the manufacturer barcode without a sticker. It does nothing for the other brands you resell, so a mixed wholesale account still needs a labelling operation.
Can my supplier or prep centre apply the labels?
Yes, and for most wholesale sellers that is the sane answer. The FNSKU is specific to your account and SKU, so whoever applies it needs the correct label file from you for that shipment. Agree the per-unit charge before March rather than discovering it on the first invoice.
Does the FNSKU label have to cover the manufacturer barcode?
Amazon's long-standing requirement is that only one scannable barcode is visible, so the original EAN or UPC gets covered rather than left beside it. Two readable barcodes on one unit is how stock is received as the wrong item.
Does this change what I pay Amazon?
Not directly — referral and fulfilment fees are unaffected. What changes is your own cost per unit: labels, printing and the time to apply them, or a prep partner's per-unit charge. That belongs in your cost of goods, where it will quietly move the ROI on low-value lines. The FBA calculator is the fastest way to see how far.
Sources
Amazon Seller Central is the authority for your own account — check the barcode requirement shown on the product and in the inbound flow before you buy labels in bulk. Background reading: GS1 UK on the new FNSKU labelling requirement.