Amazon FBA Prep and Labelling at the Chinese Factory: Getting It Right Before the Container Loads

Our FBA sourcing playbook covers product selection, factory choice, freight and the tariff maths. This guide picks up where that one stops: the physical prep and labelling work, and whether the Chinese factory should be doing it. A factory that builds an excellent product can still pack it in a way that costs you weeks at the fulfilment centre — and by the time you find out, the goods are in another country and the supplier has been paid.

Table of contents

1. Two rulebooks, two enforcers
2. FNSKU vs UPC/EAN — which barcode goes on the unit
3. Polybags, suffocation warnings and bag sizing
4. Carton labelling: shipment labels vs carton content labels
5. Carton weight and dimensions
6. Bundles, multipacks and "sold as set" marking
7. Expiry-dated and lot-coded goods
8. Country-of-origin marking is a customs requirement
9. Who applies the labels
10. Writing prep into the purchase order
11. What to inspect before the container loads

1. Two rulebooks, two enforcers

Two independent rule sets apply to an FBA carton, and importers conflate them.

Amazon's rules are commercial. They exist so a fulfilment centre can receive, scan and pick your units without a human making a judgement call. Breach them and Amazon charges you, receives you slowly, or refuses the delivery.

Customs rules are legal. They exist so the importing country knows what arrived, from where, and whether it is lawful to sell. Breach them and you face detention, marking duties or seizure.

Neither party checks the other's rules. Specify both, separately.

One caveat runs throughout: Amazon publishes current requirements per marketplace in Seller Central, and changes them. Thresholds, fees, label formats and warning wording differ between the US, UK and EU stores and have all moved recently. This guide gives the shape of each requirement so you know what to look up; it is no substitute for the live rule.

2. FNSKU vs UPC/EAN — which barcode goes on the unit

Two barcode models exist, and the choice is a listing setting, not a factory decision.

Manufacturer barcode (UPC/EAN). Amazon identifies the unit by its own GTIN and commingles your stock with every other seller's of that GTIN. It saves the cost of a label, but a customer buying from your listing can be shipped somebody else's unit — and their quality or counterfeit problem becomes yours.

Amazon barcode (FNSKU). A code unique to your seller account and SKU; your units are stored and picked as yours. Nearly every private-label seller uses it, because it is the only version of FBA in which the unit the customer receives is the unit you inspected.

At the factory:

• You generate the label file in Seller Central; the factory prints and applies it. A supplier offering to "make the barcode for you" is telling you what else they improvise.
• The FNSKU must be the only scannable barcode on the outside. If retail packaging carries a UPC, the label covers it — two live barcodes means one eventually gets scanned in error.
• The GTIN still matters. Amazon validates GTINs against the issuing registry, so cheap resold barcodes can fail listing creation though they scan fine.
• Print quality is a defect class. Fading thermal stock, low-resolution printing, labels over a curve or a seam, labels under glossy film. Specify stock, adhesive and a flat placement zone.

3. Polybags, suffocation warnings and bag sizing

Most soft goods, textiles and anything with loose parts or an openable retail box has to arrive in a sealed transparent bag. The requirement set is consistent in shape even as the figures move:

• A minimum bag thickness, so bags don't split in a pick tote.
• A transparent bag, with the barcode outside or fully scannable through the film.
• A sealed bag. Folded over and taped is not sealed.
• A suffocation warning above a defined bag opening size. Wording, minimum print size and threshold are published by Amazon and differ by marketplace; for UK and EU shipments expect to need the destination languages.
• A bag size specified per SKU. Oversized bags waste space and trigger re-bagging charges.

Two failures recur: printing the warning at whatever size fits the film already on the floor, and bagging the unit but applying the FNSKU to the product box inside the bag, where it cannot be scanned. Both are trivial to catch on a golden sample and expensive to fix in a container.

4. Carton labelling: shipment labels vs carton content labels

Two labels, two jobs — and confusing them is the commonest carton-level failure we see.

The FBA shipment box ID label ties the box to one inbound shipment. Amazon generates it once a shipment plan exists, and every box gets a unique label. They cannot be photocopied — duplicating one across a pallet is a guaranteed receiving problem, and it is exactly what a factory does when sent one PDF and told to "put this on the cartons".

Carton content information states what is in each box: SKUs, counts, and where relevant expiry data. It can be printed as 2D carton content labels or submitted electronically. Omitting it does not necessarily stop receipt, but Amazon applies a manual processing charge for boxes it has to open and count, and receiving slows markedly.

Alongside sit the ordinary trade markings your forwarder needs — PO number, SKU, quantity, carton number, gross and net weight, origin marking.

The timing conflict is unavoidable: box ID labels usually cannot exist while the factory is packing, because there is no shipment plan until quantities are final and Amazon may split the shipment across centres. That is the structural reason prep gets divided between China and the destination — section 9.

5. Carton weight and dimensions

Amazon publishes a maximum weight and maximum dimensions for inbound boxes, a separate allowance for a box holding a single oversize item, and required heavy-box markings (the "Team Lift" and "Mech Lift" style labels) above defined weights. Check the current figures for your marketplace; they differ by store and have changed.

The consequences stay stable even when the numbers don't:

• An over-limit box can be refused at the door, leaving a container-load problem in a country you are not in.
• More often it is received and surcharged — to you, not the factory.
• Repacking at destination costs more per unit than getting the carton right at source, and destroys carton content accuracy.

So set units per carton such that packed weight sits well under the ceiling, and check dimensions against both Amazon's limits and your container maths — our CBM calculator and the LCL vs FCL guide cover the freight half. Write the ceiling in as a contractual maximum and verify it on calibrated scales at inspection: factories drift upwards on carton fill to save cartons and freight, and will not tell you.

6. Bundles, multipacks and "sold as set" marking

A bundle or multipack is one sellable unit as far as Amazon is concerned, and has to physically behave like one.

• Components secured together so they cannot separate in handling — bagged, banded, or in one outer box.
• The unit marked as a set, saying it is sold as a set and must not be separated. That wording is aimed at the centre associate who would otherwise reasonably shelve four items.
• Only the bundle's barcode scannable. Cover every component barcode, or a four-pack with four live UPCs gets received as the wrong thing.
• For multipacks, the quantity obvious from the outside.

Bundling at the factory is far cheaper than at destination, and for kits with custom inserts it is the only sensible option. The trade-off is flexibility: once 3,000 units are bundled four-up in a Chinese warehouse you cannot sell them singly without unpacking them somewhere expensive. Bundle at source when the bundle is the product; bundle at destination while you are still testing what sells.

7. Expiry-dated and lot-coded goods

Anything with a shelf life — supplements, cosmetics, food, some consumables — carries a layer factories under-deliver on, because Chinese domestic practice differs.

The shape: the expiry date on the unit and the outside of the carton, in the format Amazon specifies for that marketplace, at a legible print size. Amazon also enforces a minimum remaining shelf life on arrival and typically requires one expiry date per box so stock can be rotated. Both are published and marketplace-specific.

What goes wrong: printing the manufacture date instead of the expiry; a domestic format that reads ambiguously abroad; an ink-jet code on a surface it rubs off; or leftovers from two runs consolidated into one carton to make the counts work. The last is the costly one — it makes the whole carton unreceivable rather than merely short-dated.

Selling here, read the food contact and FDA/EU guide too; those obligations sit on top of Amazon's, not instead of them.

8. Country-of-origin marking is a customs requirement

This is the section importers skip, and the one with legal rather than commercial consequences.

United States law requires imported articles to be marked with their country of origin in a conspicuous place, as legibly, indelibly and permanently as the article permits, so the ultimate purchaser can see it. That obligation sits in the tariff act and is enforced by customs at the border, not by Amazon. Where the article cannot practically be marked, the marking goes on the container the buyer receives. Failure can mean detention, marking duties or refused entry.

UK and EU practice differs: no single horizontal "made in" mandate covering all goods, but various product categories carry their own origin and labelling rules, and any origin claim you do make must be accurate under consumer-protection law.

Three consequences for a China order:

1. Marking must be permanent where the article allows it. A peeling sticker is not compliant on something that could be moulded, printed or woven. Factories default to stickers because stickers are nearly free.
2. The polybag and the retail box are separate marking surfaces from the unit. Work out which one the customer actually sees.
3. A "made in" claim has to survive scrutiny. Goods finished in a third country from Chinese components raise a real legal test, not a marketing choice — our tariffs guide covers substantial transformation.

9. Who applies the labels

Four options, and most established sellers use a split.

At the factory. Cheapest by a wide margin, and right for everything unit-level: bagging, warnings, FNSKU, bundle marking, origin marking, expiry printing. The weakness is recourse — find a wrong FNSKU after the container sails and your options are a rework you pay for, or a claim against a supplier already paid.

At a consolidator or forwarder in China. Rework is still cheap, and a competent consolidator can label several suppliers' goods before one container is packed. You pay a handling leg, and many consolidators cannot actually do prep work.

At a destination 3PL or prep centre. Per-unit cost and added lead time, but the goods are in your control before Amazon sees them: box ID labels against a real shipment plan, fixable errors, inventory held back during a launch. We name no providers; what matters is whether they follow a written prep spec, photograph exceptions, and handle a wrong arrival properly.

Amazon's own prep service. Convenient, and it ends any argument about fault. Also the least flexible, it cannot fix an incorrect FNSKU, and you pay centre rates for warehouse work.

The pattern that works: unit-level prep at the factory, shipment-level labelling at the destination.

10. Writing prep into the purchase order

None of this is enforceable as an email. Our purchase order essentials guide covers the contract stack; here is the FBA layer that drops into it.

Make prep a numbered exhibit to the PO, referenced from the specification clause. "Packaging as per FBA requirements" is not a spec — the factory's understanding of FBA requirements is the exact problem you are solving. State, per SKU: bag material, thickness and dimensions; seal method; warning wording and language; label file source, stock, size and placement zone with a photo; unit and inner counts; master carton dimensions and maximum gross weight; carton markings with a mock-up; origin marking method and location; and for dated goods, date format and minimum shelf life at shipment.

Name a golden unit and a golden carton — one prepped unit and one fully packed master carton, approved before mass production, photographed and named in the contract as reference samples (sample approval workflow).

Put labelling into the remedies ladder. Prep failures are reworkable, so the remedy is rework at supplier cost then re-inspection at supplier cost. Say what happens when a rework fails twice.

Know where your leverage sits. Under Alibaba Trade Assurance the escrow releases to the supplier on shipment, not on your receipt of the goods, so a labelling defect found at a fulfilment centre is found after the money has gone. The protection is a balance released only against a passed pre-shipment inspection with prep inside its scope.

11. What to inspect before the container loads

Prep and labelling belong in the pre-shipment inspection scope, and must be in the defect classification schedule to be caught. AQL is a sampling standard, not a defect rate — an inspector without classification guidance will log an unscannable barcode as a minor packaging issue, when for an FBA shipment it is the defect that costs you most. Classify barcode and warning failures as Major or Critical, and follow the FBA playbook's advice to tighten the major tolerance below the 2.5 default.

Checks worth naming in the scope:

• Scan every barcode with a real scanner, not by eye. Confirm the scanned FNSKU matches the intended SKU and that no second barcode will scan.
• Confirm the warning text — wording, language, print size, and that it is on the bag rather than a card inside it.
• Check the bag — transparent, sealed, right size, right thickness, barcode readable as presented.
• Weigh and measure packed cartons on calibrated equipment, against the contractual ceiling rather than the packing list.
• Verify carton contents against carton markings, opening cartons from across the lot rather than the top of the pallet.
• Check origin marking is present, permanent where required, and on a surface the buyer sees.
• For dated goods, confirm format, remaining shelf life, and that no carton mixes dates.
• Photograph all six faces of a sealed carton and every label type, so a destination dispute has evidence.

We build these into the pre-shipment scope as standard for FBA clients on our quality control service, because in this segment packaging defects do more financial damage than product defects.

The rejection causes that keep repeating: unscannable or faded FNSKUs; a live manufacturer barcode left uncovered; missing or wrong-language suffocation warnings; one box ID label duplicated across cartons; carton content information never submitted; cartons over the weight ceiling; labels over seams, corners or shrink wrap; bundle components neither secured nor marked as a set; and mixed expiry dates in one box.

The bottom line

FBA prep is not a packaging afterthought. It is a specification problem, and it fails for the reason most China sourcing problems fail: the requirement was communicated informally and never verified.

Decide the barcode model before artwork. Write a prep exhibit into the PO with a golden unit and a golden carton behind it. Do unit-level prep in China where it costs almost nothing, and shipment-level labelling wherever the shipment is planned. Look up Amazon's live requirements for the marketplace, because they move. Keep customs marking as a separate line item, because nobody at Amazon checks it for you. Then inspect all of it before the container loads.

If you'd like our team to write the prep exhibit, approve the golden carton and run the pre-shipment scope on an FBA order, get a quote.

Related: How to source for Amazon FBA from China · Purchase order and contract essentials · AQL inspection 2.5 explained · Sample approval workflow