Amazon doesn't reject shipments because your product is wrong. It rejects them because a label is in the wrong place, a poly bag has no suffocation warning, or a carton is a pound over the limit. Prep is a compliance exercise, and it's entirely learnable.
The requirements that actually cause problems
Labels
Every unit needs a scannable FNSKU label, and it has to cover the manufacturer's original barcode completely. A visible second barcode is the classic rejection — the scanner reads whichever it sees first, and if that's the UPC, your unit is now attributed to somebody else's listing.
Poly bags
Any bag with an opening of 5 inches or more needs a suffocation warning. The bag has to be transparent, sealed, and the barcode has to be scannable through it. This is the single most common prep failure on apparel and soft goods.
Sets and multipacks
Anything sold as a set must be labeled so it can't be broken apart in the fulfillment center. "Sold as set, do not separate" exists for a reason. A set that gets split becomes two units of something that doesn't exist.
Fragile and liquid items
Glass and liquids need bubble wrap or a bag depending on the category. The rule is written around what survives being dropped, not what looks tidy.
Carton limits
Standard cartons cap at 50 lbs; anything heavier needs a team-lift label, and there's a hard ceiling above that. Cartons also have maximum dimensions. Going over doesn't get flagged politely — it gets refused at receiving.
Box content information
Amazon needs to know what's in each carton before it arrives. Skipping it triggers a per-unit fee that quietly eats the margin you were protecting by prepping yourself.
Prep it yourself, use Amazon, or use a 3PL
Yourself is cheapest per unit if your volume is small and your time is genuinely free. It stops being cheap the moment you're labeling four thousand units in a garage.
Amazon's own prep service is convenient and priced per unit. Fine for small volumes; expensive at scale, and you lose the chance to catch a quality problem before it reaches a customer.
A 3PL makes sense when your freight arrives by container anyway. The container gets received, inspected, prepped, labeled and shipped to the fulfillment centers as one flow — instead of importing to yourself, storing at home, then re-shipping. That's the whole argument: it removes a leg.
The failures worth designing out
- Wrong or unscannable FNSKU — the top cause of unfulfillable inventory.
- Original barcode still visible under or beside the FNSKU.
- Missing suffocation warnings on poly-bagged goods.
- Overweight cartons with no team-lift label.
- Shipping to the wrong fulfillment center because the plan was regenerated after cartons were labeled.
- Sending everything to one FC when the plan split it — a rejection waiting to happen.
Where inspection pays for itself
Prep is the last moment anyone looks at your product before a customer does. If you import, that's worth using. Catching a damaged run, a wrong colourway or a missing accessory at the warehouse costs a re-pack; catching it through Amazon reviews costs the listing. Pair prep with quality inspection when the shipment is new, from a new supplier, or high value.
Don't forget the freight side
The shipment still has to get to the fulfillment centers, usually as LTL on pallets. Palletizing to Amazon's standard — proper stacking, wrap, and pallet labels on all four sides — is part of the job. See LTL freight.
Long Road Warehouse handles FBA prep alongside receiving, storage and fulfillment in Kent, WA — so imported freight can go container to FC without an extra stop. Request a quote.
