The definitive Amazon FBA prep guide for 2026. Learn every requirement: FNSKU labeling, poly-bagging, bubble-wrapping, carton creation, shipment plans, and how a prep center saves you time and money.
Amazon FBA prep is the process of preparing your products to meet Amazon's strict fulfillment center requirements before shipping. When sellers send inventory to Amazon fulfillment centers (FCs), every unit must be labeled, packaged, and documented according to Amazon's current guidelines. Failure to comply results in rejected shipments, stranded inventory, and additional prep fees charged by Amazon.
At its core, FBA prep includes: receiving and inspecting incoming units, applying FNSKU or barcode labels, poly-bagging or bubble-wrapping items that require it, creating carton contents lists and applying box labels, building shipment plans in Seller Central, and physically shipping to the assigned Amazon FC.
For most sellers, the choice comes down to: self-prep (doing it yourself) or outsourcing to a third-party prep center. As volume scales past 500-1,000 units per month, the economics strongly favor a professional prep center.
FNSKU (Fulfillment Network Stock Keeping Unit) is Amazon's internal identifier for each product-seller combination. Unlike UPC or EAN codes, which identify a product universally, FNSKU is unique to your seller account. This means Amazon can trace every unit back to you specifically — which matters for co-mingling, returns, and liability.
Key FNSKU labeling rules:
• Labels must be scannable — no wrinkles, folds, or damage
• Size: minimum 1 × 2 inches
• Each unit must have exactly ONE scannable barcode visible
• Labels must be applied over the original manufacturer barcode (or set to the side if there's no conflict)
• Label placement: on the outside of the packaging, not on clear poly bags where it can shift
• Font requirements: Code 128 or QR codes are acceptable
At QuickShipment, we print and apply FNSKU labels from our Claymont, Delaware facility. Every label is verified with a scan before the unit leaves our hands — our 99.8% acceptance rate reflects this rigor.
Amazon requires poly-bagging for any product that can:
• Spill, leak, or contaminate other products
• Be damaged by moisture or dust during transit
• Contain multiple loose pieces that could scatter
• Includes any product over a certain weight or size threshold
Poly-bag specifications:
• Minimum 1.5 mil thickness for bags under 12" × 12"
• Minimum 2 mil thickness for bags 12" × 12" or larger
• Must include a suffocation warning for bags with an opening of 5" or larger
• Bag must be sealed (heat-sealed or taped)
• FNSKU label must be on the outside of the bag and fully scannable
Common mistakes: using bags that are too thin, forgetting the suffocation warning, or placing the FNSKU inside the bag instead of outside. Any of these will result in rejection at the FC.
Bubble wrap is required for fragile products — specifically anything that could break, crack, or be damaged during transport or FC operations. Amazon's guidelines are not always explicit about which products require bubble wrap, which creates ambiguity. The rule of thumb: if your product could break in a box that's dropped from 4 feet, bubble-wrap it.
Bubble-wrap prep specifications:
• Minimum 2 inches of bubble wrap on all sides
• Product must not move when the package is shaken
• Bubble wrap must be secured (not loose)
• No sharp corners or edges should protrude through the wrap
• FNSKU label must remain visible and scannable
For glass, ceramic, electronics, and delicate home goods: bubble-wrapping is almost always required. For clothing, soft toys, and plastic products: usually not required, but poly-bagging typically is.
When your inventory arrives at an Amazon FC, each carton must be labeled with:
• An Amazon FBA box label (downloaded from Seller Central after creating a shipment plan)
• The box label must cover or supersede any existing shipping labels
• Each box is assigned a unique box ID — do not mix box IDs between cartons
Box content requirements:
• Maximum weight: 50 lbs per box (exception: single items over 50 lbs get special handling)
• Maximum dimensions: no more than 25" on any side
• Liquids must be in leak-proof packaging within the box
• Box must not bulge or be difficult to close
• Do not use shoe boxes or other retail packaging as the shipping carton
A carton contents list (listing which FNSKUs and quantities are in each box) is required for all shipments. This is generated in Seller Central during shipment creation.
The shipment plan is your 'shipping manifest' — it tells Amazon exactly what's coming, in how many boxes, to which FCs. Here's the process:
1. Go to Seller Central → Inventory → Manage FBA Inventory
2. Select the products you're sending
3. Enter the quantities per unit
4. Amazon assigns one or more FCs (you may get split shipments)
5. Set box content information (how many units per box, weight, dimensions)
6. Print Amazon FBA box labels
7. Schedule a pickup or drop-off with your carrier
Key gotchas: Amazon frequently splits shipments between multiple FCs, which increases shipping costs. Amazon's Inventory Placement Service (now renamed and restructured) allows you to ship to one FC for a fee — but this fee can be substantial. Many sellers use prep centers on the East Coast (like our Claymont, DE facility) to minimize transit time to Amazon's East Coast FCs.
FBA prep costs typically range from $1.00 to $2.50 per unit for standard prep, depending on volume:
• Self-prep: Labor ($15-20/hr) + materials + space = $1.50-$3.00+ per unit at low volumes
• DIY at scale: Can get to $0.75-$1.00/unit but requires significant fixed overhead
• QuickShipment rates: $1.00-$2.00/unit (volume dependent), FNSKU labeling included, no setup fees
Hidden costs of self-prep that sellers underestimate:
• Warehouse rent or home space costs
• Supplies (labels, poly bags, bubble wrap, tape, boxes)
• Labor for packing, labeling, and shipping
• Carrier account negotiations
• Amazon rejection rework time
For most Amazon sellers doing 500+ units/month, outsourcing to a prep center like QuickShipment is less expensive than self-prep once all costs are factored in.
One of the most underutilized advantages for Amazon sellers is choosing a prep center in a zero-sales-tax state. Delaware has 0% sales tax — one of only five US states. When your products flow through our Claymont, Delaware warehouse, every purchase is made in a sales-tax-free state.
On a $10,000 monthly inventory purchase:
• California (9.5% tax): $950 in monthly taxes = $11,400/year
• New Jersey (6.625% tax): $662.50/month = $7,950/year
• Delaware (0% tax): $0. Every year.
For sellers spending $100,000-$500,000 annually on inventory, the Delaware tax advantage alone pays for years of prep center fees. This is 100% legal — it's not a loophole, it's Delaware law.
500+ sellers trust QuickShipment. Delaware tax advantage + 48-hour prep + 99.8% acceptance rate.
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