The Amazon FBA prep checklist
Amazon's fulfillment centers move at machine speed, and a unit that arrives loose, unscannable, or damaged gets flagged before it reaches a customer. Prepping correctly the first time is the difference between a clean check-in and a stranded, unsellable shipment.
THE SHORT ANSWER
Prepping a unit for Amazon FBA means getting it to arrive scannable and undamaged. Classify the unit, bag and seal anything loose or fragile, add a suffocation warning if the bag is large, apply the FNSKU barcode where it can be scanned, and pack everything in a shipping box within Amazon's inbound size and weight limits. Because Amazon has wound down much of its US FBA prep service, sellers now do most of this work themselves — and because the rules change, every step below should be confirmed against the current version in Seller Central.
- Classify — decide whether the unit needs bagging, boxing, wrapping, or nothing
- Bag & seal — loose, sharp, or fragile units go in sealed poly bags or boxes
- Warn — poly bags with a large opening generally need a suffocation warning
- Label — apply the FNSKU so it scans without opening the package
- Box & cap — ship in a carton within Amazon's inbound size and weight limits
Requirements and fees change. This page was last verified against Amazon Seller Central on 18 July 2026. Always confirm the current version in Seller Central before you rely on it. This is general guidance, not legal or compliance advice.
Why FBA sellers prep their own units now
"Prep" is everything you do to a product between the end of your production line and the moment it is checked into an Amazon fulfillment center. For years many sellers leaned on Amazon's own prep services to bag, box, or label units on arrival. Amazon has since wound down much of that US FBA prep service, so for most sellers the reality is now self-prep: you own the outcome, and a unit that shows up wrong is your problem to fix — often remotely, after it has already shipped.
That shift matters because the cost of getting it wrong is no longer just a rejected box. When a unit arrives improperly prepped, Amazon may prep it for you and bill a per-unit charge, or the shipment can be held while you sort it out. We are deliberately not quoting a number: Amazon publishes a prep-fee schedule and it changes, so check the current amounts in Seller Central. The point is structural — prep you do once, correctly, at the spec stage is far cheaper than prep imposed on you after the fact.
This checklist is the FBA-specific slice of a bigger picture. FBA is one lane among several, and the same product often needs different packaging for retail shelves or direct-to-consumer parcels — that is the subject of our guide to packaging requirements by sales channel. For the full rulebook behind the steps below, see Amazon FBA packaging requirements in plain language.
The FBA prep checklist, step by step
Work the list in order. Each step has a "verify" note because the specifics — thresholds, exact wording, placement rules, and caps — are Amazon's to set and are subject to change. Treat the numbers Amazon publishes as authoritative and this checklist as the structure that keeps you from missing a step.
- Classify the unit. Decide what category the product falls into — poly-bagged, boxed, bubble- wrapped, taped/sealed, or sold as a set. Classification drives every step after it, so get it right first. Verify the prep category for your product type in Seller Central.
- Bag and seal if needed. Loose, dusty, granular, sharp, or easily-separated items generally need to be fully enclosed and sealed — a poly bag or a box — so nothing escapes or contaminates other inventory. Confirm whether your product requires bagging.
- Add a suffocation warning if the bag is large. Poly bags at or above a threshold opening size generally carry a suffocation warning (commonly published as 5 inches or more — verify against Seller Central). Print it on the bag or apply it as a label.
- Protect fragile units. Glass, liquids, and breakables typically need bubble wrapping or a rigid box so they survive fulfillment-center handling. Match the protection to the failure mode you are guarding against.
- Apply the FNSKU label. Place Amazon's fulfillment barcode (FNSKU) on the outside of the unit where it scans without opening the package, and cover any other scannable barcode that could be read by mistake. Verify placement guidance in Seller Central.
- Pack into a shipping box within limits. Build your case pack and outer shipping box to sit inside Amazon's inbound size and weight limits, and mark heavy boxes as required.
- Apply the shipment box labels. Each box in an inbound shipment carries the shipment/box ID label Amazon generates in the workflow. Apply it flat, on the outside, where it will not be covered by tape or a seam.
Those seven steps are the whole job for most SKUs. The rest of this page unpacks the ones people get wrong most often — bags and warnings, labels, and box limits.
Prep by unit type
Different products demand different prep. Use this as a quick-reference map, then confirm the exact requirement for your item — Amazon's category rules are the source of truth, and this table is only a starting frame.
| Unit type | Common prep | Verify at |
|---|---|---|
| Loose / granular / dusty | Fully enclosed and sealed in a poly bag; suffocation warning if the bag is large | Seller Central |
| Sharp or protruding | Bagged or boxed so edges can't puncture other units or workers | Seller Central |
| Fragile (glass, liquids) | Bubble-wrapped or in a rigid box able to survive handling | Seller Central |
| Sold as a set / multi-pack | Marked and bagged as a single sellable unit so it isn't split | Seller Central |
| Already in retail packaging | Often ships as-is if the packaging is durable and the FNSKU is applied | Seller Central |
| Oversize / heavy | Boxed to strength, with team-lift or heavy markings where required | Seller Central |
The recurring theme is enclosure and scannability: each unit must arrive contained, undamaged, and readable by a scanner. If your product's own retail packaging already does that, you are close to done. If it doesn't, the added bag, box, or wrap is the prep.
Poly bags, sealing, and suffocation warnings
Bagging is where most first-time prep goes sideways. A compliant poly bag is generally expected to be transparent, made to a minimum film thickness, sealed shut, and to show a scannable barcode — either through the bag or as a label on the outside. The exact thickness and the barcode rules are Amazon's to publish, so we won't restate a number here; the deep-dive on those specifics lives in our Amazon FBA poly bag requirements article, and the current figures live in Seller Central.
The one rule worth committing to memory is the suffocation warning. It is commonly published that a poly bag with an opening of 5 inches or more (measured flat) requires a suffocation warning — a widely-repeated, stable rule, but still one to verify against Seller Central before you print. How the warning is worded and how its text size scales with bag size are set by Amazon and its safety references, which is exactly what our suffocation warning label requirements guide covers. Do not invent a font size or a wording — pull the current spec.
Practically, the warning lives one of two ways: printed directly into the bag's plate art, or applied as a separate label. Both are ordinary flexible-packaging and label jobs, and choosing between them is usually a question of order volume and how many SKUs share the bag. Either way, keep the warning legible and inside the printable area of the bag.
Labeling: the FNSKU and the box
Two labels matter at prep time, and they do different jobs. The FNSKU is Amazon's fulfillment barcode for a specific SKU under your account; it is what a fulfillment-center scanner reads to identify a unit. It generally goes on the outside of the unit, positioned so it can be scanned without opening the package, and it should cover any manufacturer barcode (like a UPC) that a scanner might read by mistake and commingle with someone else's inventory. Placement and print-quality guidance are published in Seller Central — confirm the current guidance there.
The second label is the box (shipment) label: the ID Amazon generates in the inbound shipment workflow, applied to each carton so the receiving dock can match it to your shipment. Apply it flat, on a visible outside face, clear of tape lines and box seams so it stays scannable. A label that is creased over an edge or buried under packing tape reads as a missing label at the dock. Both labels reward a substrate that stays legible and adhered through a rough transit — worth getting right once rather than reprinting a rejected run.
The shipping box: size and weight limits
The outer shipping box that carries your units to the fulfillment center is not a free-for-all. Amazon publishes standard inbound box size and weight caps, with some exceptions for heavier individual units and required team-lift or heavy markings above certain thresholds. We are not stating the exact inch or pound figures as fact here — they change and they are Amazon's to set — so treat the numbers in FBA box size and weight limits as the map and Seller Central as the current territory.
Case pack — a fixed, uniform quantity of a single SKU packed together in one shipping box, so the whole box can be received as one line. See more terms in the packaging glossary.
The design lever you actually control is the case pack itself. Right-sizing the master carton so it holds a clean quantity of units and lands comfortably inside the caps pays off twice: it keeps you inside Amazon's limits and it trims the dimensional weight you pay to get the box there. A box that is under-filled ships air; a box that is over-spec'd is heavy and can crush. If your cases arrive crushed or your board feels light for the load, that is a strength question — see corrugated box strength — worth solving before it becomes damaged inventory.
Check your prep before you ship
The whole point of a checklist is to catch a miss while it is still cheap to fix. Two tools make that concrete. Run the unit through the FBA prep checker to walk the requirements interactively and confirm you have covered bagging, sealing, warnings, labeling, and box limits for your product type. Then, once the prep is settled, capture it as a spec sheet so your bag, label, and carton specs live in one document your supplier and your team can both work from.
- Before the first order — use the prep checker to classify the unit and list its required steps.
- Before you approve artwork — confirm the suffocation warning, FNSKU space, and bag transparency are all designed in.
- Before every reorder — re-verify against Seller Central, because a rule may have moved since your last run.
How PackOS helps you prep once
PackOS sits at the spec stage, before any of this becomes a fulfillment-center problem. When you bring a product to a quote, it detects the structure, dimensions it, and prices the bag, label, or carton — which means the suffocation warning, the FNSKU space, the bag transparency, and the case-pack dimensions can all be designed in from the start rather than discovered at the dock. Because the model is parametric, sizing a master carton to sit inside Amazon's limits is a dimension change, not a redraw. You can see how the logistics side of that works on the technology page, or run a real bag or box through Quick Quote. Prep once, spec it, and let the reorders take care of themselves.
Frequently asked questions
Do I have to prep my own units for Amazon FBA now?
In most cases, yes. Amazon has wound down much of its US FBA prep service, so sellers are increasingly responsible for prepping units before they ship to a fulfillment center. What prep a given product needs depends on its type and condition, and the current rules live in Seller Central. Confirm your product's requirements there before each shipment.
What is FBA prep, exactly?
FBA prep is the work of getting a unit ready to arrive at an Amazon fulfillment center undamaged and scannable. It typically covers bagging or boxing loose or fragile items, sealing, adding any required warnings, and applying a scannable FNSKU barcode. The exact steps vary by product type, so verify the current requirements in Seller Central.
When does a poly-bagged unit need a suffocation warning?
A suffocation warning is commonly required when a poly bag's opening is 5 inches or more, measured flat. This is a widely published rule, but the exact threshold and wording can change, so confirm the current requirement in Seller Central before you print the bag or label.
Where does the FNSKU barcode go on an FBA unit?
The FNSKU generally goes on the outside of the unit, positioned so it can be scanned without opening the package and so it covers any other barcode that could be read by mistake. Placement details are published in Seller Central, so verify the current guidance there.
What happens if my box is over Amazon's size or weight limit?
Boxes over Amazon's inbound size or weight limits can be flagged, refused, or subject to extra handling requirements such as team-lift markings. Amazon publishes standard box size and weight caps with some exceptions for heavier units, so check the current limits in Seller Central and right-size your case pack to fit.