Amazon Barcode Requirements (2026)
UPC, EAN, FNSKU — Explained

Which Barcode Goes on the Unit — the Decision in One Table

Almost every barcode question reduces to one choice: does Amazon track this unit by the manufacturer's barcode, or by an Amazon barcode you apply? Get that right and the rest follows.

Amazon's own documentation sets out when its barcode is mandatory rather than optional — used condition, no scannable UPC, media, restricted or dangerous goods, and consumable or topical products among them.

What Commingling Actually Costs You

Using the manufacturer barcode puts your units in a shared pool with every other seller of that ASIN. Amazon may ship any unit from that pool against your order. The saving is real — you skip a labelling step — and so is the risk:

• You inherit other sellers' quality. If a counterfeit or damaged unit enters the pool, it can ship against your listing and the complaint lands on your account.
• Returns are not necessarily your units. What comes back is whatever the customer received.
• Inauthentic claims are difficult to defend when you cannot prove the shipped unit was yours.

For most private-label and brand-registered sellers the arithmetic is not close: FNSKU labelling costs cents, an inauthentic complaint costs a listing. We include FNSKU labelling in FBA prep at every volume tier for exactly this reason.

Getting a UPC Properly — and Why Cheap Ones Fail

If your product has no manufacturer barcode you need a GTIN before you can create the listing. GS1 is the only issuing authority, and Amazon validates the prefix against the GS1 database.

• Single GTIN — GS1 US licenses individual GTINs for a one-off fee, currently around $30 each with no annual renewal. Right for a handful of SKUs.
• Company prefix — from roughly $250 upward depending on how many products you need to identify, with an annual renewal. Right once you are past a dozen SKUs.
• Resold or "cheap" UPCs — codes bought from third-party resellers were issued to a different company. The GS1 record shows that company's name, not yours, and Amazon rejects the mismatch. This is the single most common listing-creation failure we see from new sellers.

Five Ways a Correct Barcode Still Fails at the Fulfilment Centre

These are what our receiving team actually catches — the label is right, the application is wrong:

1. Printed with "fit to page" enabled. The barcode scales down, the quiet zone narrows, and it scans on a desk but not on a moving belt. Print at 100%, always.
2. Applied over a seam, corner or curve. The scanner needs a flat plane. A label bent around an edge reads intermittently, which is worse than not reading at all.
3. An old barcode left showing. The most common cause of a unit being logged against the wrong ASIN. Every other barcode must be fully covered — not crossed out.
4. Thermal label on a hot pallet. Direct thermal darkens with heat and pressure. For summer sea freight, laser or thermal-transfer labels survive better.
5. Label under shrink wrap that wrinkles. The wrap distorts the bars. Label the unit, then wrap — not the other way round.

Barcodes on the Carton Are a Different System

Unit barcodes identify products; carton labels identify boxes. They are generated separately in Seller Central during shipment creation, and a carton needs its own label on the outside even if every unit inside is already labelled. A shipment that arrives with perfect unit labels and no carton label still gets held.

Full detail is in our shipment plan guide; the labelling mechanics themselves are in the FBA labelling guide.

Frequently Asked Questions

Do I need an FNSKU or is a UPC enough?
A UPC is enough only if you deliberately choose commingled inventory and the product is new, unrestricted and not expiry-dated. For everything else Amazon requires its own barcode. Most sellers use FNSKU by choice because it keeps their units separate from other sellers'.

Where do I get a UPC for a new product?
From GS1, the only issuing authority. A single GTIN is currently around $30 as a one-off; a company prefix starts near $250 with annual renewal. Codes bought from resellers show another company's name in the GS1 record and Amazon rejects them.

What is the most common barcode mistake?
Printing at anything other than 100% scale. "Fit to page" narrows the quiet zone around the bars, and the label then scans by hand but fails on a fulfilment-centre belt.

Can I put the FNSKU over the existing UPC?
Yes, and you should — provided it fully covers it. A partially visible barcode underneath is worse than a clean cover-up, because the scanner may read the wrong one.

Do cartons need barcodes too?
Yes. Carton labels are generated separately during shipment creation and go on the outside of each box, regardless of whether the units inside are already labelled.