FBA Labelling UK: Amazon Barcode (FNSKU) or Manufacturer Barcode?
Every unit you send to FBA has to be identified by a barcode Amazon can scan. You can use the product's own barcode or an Amazon barcode tied to your account. For resellers, that choice decides whose stock your customer actually receives. Here is how it works and how to label properly.
An Amazon barcode (FNSKU) links each unit to your seller account. A manufacturer barcode (EAN or UPC) can let Amazon treat your units as the same as other sellers' units of that product. Most UK resellers label every unit with an FNSKU so that a complaint about another seller's stock cannot land on them. Cover the original barcode, use one scannable label per unit, and prep to Amazon's packaging rules.
The two barcode types
| Barcode | What it identifies | What it means for you |
|---|---|---|
| Amazon barcode (FNSKU) | Your specific offer on that ASIN. For most products it begins with “X00”. | Your units stay your units. You print and apply the label (or pay Amazon or a prep centre to). |
| Manufacturer barcode (EAN/UPC) | The product itself, shared by every seller of that product | No labelling, but where the product is eligible, Amazon may store and ship identical units from several sellers together. |
The barcode preference is set in your FBA settings and can be changed for individual products. Amazon has changed how manufacturer-barcode stock is handled in some marketplaces, so check the current options and wording in Seller Central before you rely on either.
Why most resellers label every unit
- Authenticity complaints. If identical units from several sellers are mixed and another seller's stock is not genuine, the customer complaint can attach to whichever seller made the sale. With FNSKU labels, the customer gets the unit you sent.
- Cleaner claims. Lost and damaged unit reimbursements are easier to trace when each unit is tied to you. See FBA reimbursement claims.
- Condition control. Your returned or damaged units are not mixed with others.
The trade-off is time. Labelling is a big part of why sellers move to a prep centre. Our guide on when to use a prep centre covers when the switch makes sense.
How to label correctly
- Print from Seller Central when you create the shipment, using the label size that matches your label sheets or thermal rolls.
- Cover every other scannable barcode on the outside of the unit, including the manufacturer barcode. A unit with two scannable barcodes can be scanned as the wrong product.
- Place the label flat on a smooth surface, not over a seam, curve or corner where it will not scan.
- One label per sellable unit. Multipacks and sets need the set marked so it is not split. Amazon's prep rules cover wording such as “sold as set” or “do not separate”.
- Scan a test label with a phone barcode app before you label a whole batch.
Prep basics that go with labelling
- Poly bags for loose or fragile items, with a suffocation warning where Amazon's rules require one, and the barcode scannable through the bag or on the outside.
- Bubble wrap or boxing for glass and breakables.
- Expiry dates clearly shown on the outside for dated products, in the format Amazon specifies.
- Products with special handling, such as aerosols, batteries or flammables, may be dangerous goods and need review before they ship. See our dangerous goods (hazmat) guide.
Amazon offers paid labelling and some prep services for eligible products, and prep centres charge per unit. Check the current per-unit fee in Seller Central and compare it with your own time before you choose. Amazon applies its own charges if units arrive without required prep or labels.
Common mistakes
- Labelling the wrong product because two similar items share a box. Label one ASIN at a time.
- Leaving the manufacturer barcode visible next to the FNSKU.
- Reusing labels printed for an older shipment after changing condition or SKU.
- Changing barcode preference while units are in transit. Settle it before you create the shipment.
Labelling and prep are steps in the buying-to-shipping workflow in the £29 Amazon FBA Playbook. If you are not live yet, start with the free UK FBA Starter Framework. For a worked sourcing example from search to shipment, see A2A arbitrage step by step.
Sources
Amazon Seller Central UK help pages on FBA product barcode requirements, barcode preference, labelling and packaging and prep requirements (login required). Rules and fees change; Seller Central shows the current position for your account.