Amazon FBA Prep Specification: Labels, Polybags and Cartons

Read the Specification as Three Objects

Amazon's prep requirements are published as a long set of pages, and the reason sellers misapply them is that the pages are organised by product type rather than by the physical objects a packing table actually handles. There are three: the unit, the bag around the unit, and the carton around the units. Each has its own set of numbers, and a shipment fails on whichever object was checked least carefully.

What follows is the specification as a packing-line operator needs to see it, with one honest caveat: these are published figures that Amazon revises, sometimes without a headline announcement. Any spec that decides whether a container gets received should be re-read on the current Seller Central page for the shipment you are creating, not taken from an article.

Object One: The Unit Label

FBA inventory that is not eligible for commingled tracking must carry an Amazon-assigned barcode, the scannable value that begins with X00 and is generated against your listing. A manufacturer barcode can be used instead only where the product and programme qualify; where eligibility is unclear, the Amazon label is the safe answer because it does not depend on how another seller's inventory is coded.

• Print area. The published guidance puts the label in the range of one to two inches tall by two to three inches wide. A label printed smaller than that fails on a handheld scanner at the angle a conveyor presents it.
• Ink and stock. Black on white, non-reflective, at a print density of around 300 dots per inch. Thermal transfer holds up better than direct thermal on long transits, which matters more for ocean freight than for air.
• Placement. One label per unit, on a face that will not be folded, cut or hidden by the next layer of packing tape.
• Overscoring. Any original retail or manufacturer barcode must be covered or defaced so that it cannot be read. Two scannable codes on one parcel is the classic cause of a receiving mismatch.

Object Two: The Bag, and the Number You Should Not Trust

Bagged units have four independent requirements: transparency, closure, warning text, and barcode visibility through the film.

The bag must be clear and single-coloured so contents are identifiable without opening it. It must be sealed — a loose sleeve is not a bag. Where the opening is large enough to enter over the head or neck, typically described as an aperture exceeding five inches, a suffocation warning must be printed on the film itself; a sticker placed over the barcode to satisfy that rule destroys the other requirement, which is why warning text is ordered pre-printed.

And here is the honest part of a spec article. Amazon's own published pages have disagreed about minimum film thickness. One page states a metric figure, another states an imperial one, and the two are not equivalent — a millimetre is roughly forty times thicker than a mil. We have seen both figures on official material, so this article deliberately does not state a number. Treat film thickness as a supplier question with a dated answer: ask your bag supplier what gauge they are quoting, write the gauge on the packing spec, and confirm it against the current Seller Central page for your category before a long run.

Object Three: The Carton, Where Limits Stack

Carton rules are where two separate ceilings interact, and exceeding either is a defect.

Two practical consequences. First, a dense product — hardware, stone, cast iron, tile, batteries — can breach fifty pounds while staying well inside twenty-five inches, so the carton must be specified by weight budget per SKU rather than by box size. Second, the "one unit only" exception is narrow, and misusing it is an avoidable defect.

Handling Marks Live in the Weight Bands

Between the general limit and the point where a carton must not be lifted by hand, Amazon requires a Team Lift marking, applied on five faces of the carton so the instruction is visible whichever way the box is stacked. Above one hundred pounds the requirement shifts to a Mechanical Lift marking, and the practical question becomes whether the fulfilment centre's equipment and your pallet configuration agree with each other.

These marks are not decorative. They determine how many people touch your carton on the inbound side, which in turn predicts whether it is opened roughly or handled carefully. A carton that is over fifty pounds and unmarked is an invitation to a single-person lift and a crushed corner.

A Pre-Dispatch Check That Catches the Usual Failure

1. Scan a sample label from every production batch with the same reader class the carrier uses — not a phone camera.
2. Weigh three cartons at random per SKU and record the figures against the carton mark, so a dispute later has a dated origin number.
3. Check that no second barcode remains scannable anywhere on the unit or the carton.
4. Hold the bagged unit up to a light source and confirm the contents and the label are both legible through the film.
5. Confirm warning text is printed on the film rather than taped over it.
6. Photograph a sealed, marked carton per shipment and keep the image with the shipment reference.

Step six is the one that changes outcomes. A dated photograph of the carton as it left the building is the cheapest evidence available when a receiving record disagrees with a dispatch record, and it costs one operator with a phone.

When the Product and the Spec Conflict

Some catalogues genuinely do not fit: a unit whose retail box carries the barcode under a sleeve flap, a fragile item whose protective foam pushes it past the dimension ceiling, a multipack the supplier ships as one carton weight you cannot split without re-bagging. The resolution is always at origin, and it always takes one of three forms — change the packing material, change the case split, or change which barcode is authoritative. Deciding that in a Chinese warehouse costs a few minutes of labour. Deciding it after a container arrives costs the whole shipment's window.

We prep to the current Amazon specification in our own Shenzhen, Suzhou and Dongguan facilities, with before-and-after photographs on every job and no minimum order quantity; the same operation has run since 2011 across 24,000 square metres of networked warehousing. Where a specification is genuinely ambiguous — film thickness being the standing example — our default is to ask the seller which reading we should hold the job to and record the answer, rather than to guess at 3 a.m. on a dispatch day.