Quick answer
For inventory shipped on or after 31 March 2026, Amazon requires resellers to put an FNSKU label on every unit, even if the product has a manufacturer barcode. Only brands with the Brand Representative role in Brand Registry are exempt, and only when the product already carries that barcode.
For years, many sellers sent stock to FBA without labelling it: the EAN or UPC on the box was enough, and Amazon could fulfil the order with identical units from another seller. That was commingling, and Amazon announced its end for inventory shipped on or after 31 March 2026. If you resell other brands, every unit you send now needs its own FNSKU label. Here is what Amazon says, who is affected, what happens to older stock and how to prepare so your next shipment does not get held up.
Amazon defines it like this: commingling meant fulfilling an order with the closest exact product match in its network, even if that stock belonged to another seller. According to its announcement, most sellers now keep inventory close to customers, so it can deliver quickly without mixing stock.
The change applies to inventory shipped on or after 31 March 2026. The rule depends on who you are and whether the product has a manufacturer barcode:
| Your situation | Product with a manufacturer barcode | Product without a manufacturer barcode |
|---|---|---|
| Brand with the Brand Representative role in Brand Registry | No Amazon label needed if you switch to the manufacturer barcode | Amazon label required |
| Reseller (without that role) | Amazon label required | Amazon label required |
Note the detail: the role is what counts. Amazon defines a reseller as anyone not enrolled in Brand Registry as a Brand Representative, and names no other exempt role.
The announcement names no countries or marketplaces, and the same thread appears on the Seller Central forums for Europe, the UK and the US. An Amazon moderator has explicitly confirmed the end of commingling for resellers in the UK, but we found no equivalent confirmation for Spain or the rest of the EU. The sensible approach is to assume the rule applies to your shipments and check each product in your Seller Central.
You do not have to remove or relabel them. Amazon has said on its UK forum that no action is needed for unlabelled stock that was already in transit or stored in its fulfilment centres before 31 March 2026, and that it will keep selling under its original SKUs. Everything you send from that date falls under the new rule.
That said, two kinds of stock now sit side by side. According to an Amazon moderator in the UK, manufacturer-barcode inventory and FNSKU inventory are tracked separately. Some sellers have complained that the newer stock ships first while the older stock ages, and Amazon has not set out a rule in those threads on which sells first. So keep an eye on the Inventory Age report and, if a batch is not moving, consider a removal order before you pay the aged inventory surcharge.
The prep guide Amazon published in July 2026 on its US seller website sets these requirements if you print labels yourself:
| Item | Requirement |
|---|---|
| Size | 1–2 inches tall and 2–3 inches wide (about 25–51 mm × 51–76 mm) |
| Printing | Black ink on non-reflective adhesive paper; a laser printer at 300 DPI works best |
| Content | Scannable barcode, FNSKU number, product title and condition (new or used) |
| Placement | A smooth, flat surface, away from corners, edges and curves |
| Old barcodes | Cover the original UPC, EAN or ISBN so it cannot be scanned by mistake |
| Bags and extra packaging | The label goes on the outside and must be readable without opening anything |
Amazon does not accept damaged or photocopied labels, and warns that it may refuse, return or repackage products with inadequate or non-compliant packaging at your expense.
Amazon used to offer to print and apply labels for a per-item fee, but it stopped doing so in the US store on 1 January 2026. We could not confirm that the service is still available in Europe, so check in Seller Central before relying on it.
It is the practice of fulfilling an order with the closest exact product match in Amazon's network, even if that inventory belonged to another seller. Amazon announced its end for inventory shipped on or after 31 March 2026.
If you are a reseller, yes: Amazon requires its label even when a manufacturer barcode exists. If you are a brand with the Brand Representative role in Brand Registry and the product has that barcode, you do not.
No. Amazon has said that unlabelled inventory already stored or in transit before 31 March 2026 needs no action and keeps selling under its original SKUs. The requirement covers what you send from 31 March 2026 onwards.
Then you need an Amazon label in every case, whether you are a brand or a reseller. The exemption only covers products that already carry a manufacturer barcode, such as a UPC or ISBN.
Not in the US: Amazon withdrew that service on 1 January 2026. We could not confirm that it is still available in Europe, so check in Seller Central for your product before relying on it.
Amazon says it does not accept damaged or photocopied labels, and warns that it may refuse, return or repackage products with inadequate or non-compliant packaging at your expense. That is why it is worth testing a label first.
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Discover ax Prep Center →Sources: Amazon announcement "Commingling practices will end effective March 31, 2026"; Amazon reply on stock in transit or stored; Amazon reply on the UK and separate tracking; Amazon reply to brand owners; Amazon prep and labelling guide; Amazon post on barcode types (predates the change); Amazon notice on the end of prep and labelling in the US; seller complaint on ASIN lists and Amazon's reply. Checked on 5 November 2026.