Amazon FBA Labeling Requirements Explained

Amazon FBA labeling requirements can look simple at first: put the right barcode on the right product and send cartons to Amazon. In practice, labeling mistakes are one of the most common reasons sellers experience receiving delays, unplanned prep fees, inventory mix-ups and shipment problems. A label that is missing, unscannable, placed on the wrong variation or applied to the wrong carton can slow down the entire inbound process.

For sellers sourcing from China, labeling is even more important because mistakes often happen before goods leave the supplier. If the wrong labels are applied at the factory and the inventory ships internationally, fixing the problem later can be expensive. A China-based FBA prep workflow helps sellers verify labels, inspect packaging, prepare cartons and ship inventory to Amazon with fewer avoidable errors.

This guide explains the main Amazon FBA labeling requirements, including FNSKU labels, manufacturer barcodes, carton labels, bundle labels, suffocation warnings and shipment labels. It also explains how to build a practical labeling checklist before sending products from China to Amazon fulfillment centers.

If you need help labeling and preparing products in China, Fyllhub provides Amazon FBA prep service, inspection, kitting, consolidation and shipping support.

Why Amazon FBA Labeling Matters

Amazon uses labels and barcodes to identify products, connect inventory to seller accounts, receive shipments, route cartons and fulfill customer orders. When the labeling system works, inventory moves through Amazon more smoothly. When labels are wrong, Amazon may not know which product has arrived, which seller owns the units or which shipment plan the carton belongs to.

Labeling affects:

• Product identification
• Inventory ownership
• Amazon receiving speed
• Shipment accuracy
• Customer order accuracy
• Returns and support issues
• Account health and seller performance

For private label sellers, labeling is also part of quality control. A product can be physically correct but operationally wrong if the barcode points to the wrong ASIN or variation. That is why labeling should be checked before shipment, not after the inventory reaches Amazon.

Key Label Types in Amazon FBA

Several label types may appear in an FBA workflow. Sellers should know what each label does and when it is required.

Manufacturer barcode

A manufacturer barcode is usually a UPC, EAN, ISBN or GTIN printed by the brand or manufacturer. Amazon may allow eligible products to use manufacturer barcodes for commingled inventory, depending on the product, category and seller settings.

Using manufacturer barcodes can reduce labeling work, but it may also mix your inventory with identical inventory from other sellers. Many private label sellers prefer FNSKU labels because they tie units more clearly to their seller account.

FNSKU label

An FNSKU is Amazon's fulfillment network stock keeping unit. It identifies a product as inventory connected to a specific seller and listing. FNSKU labels are commonly used for private label products, products without eligible manufacturer barcodes or products where the seller wants stronger inventory separation.

An FNSKU label must be scannable and placed on each sellable unit. If the product has another visible barcode, the old barcode may need to be covered so Amazon scans the correct FNSKU.

Carton label

Carton labels identify boxes in an inbound shipment. They help Amazon receive cartons and match them to the shipment plan. Each carton going to Amazon generally needs the correct shipping label generated from the seller's shipment workflow.

Carton labels should be printed clearly, placed on a flat surface and protected from damage. If cartons are reused, old labels and barcodes should be removed or covered.

Pallet labels

For palletized shipments, Amazon may require pallet labels. These labels help identify pallets and support receiving at the fulfillment center. Pallet requirements vary based on shipment method and destination.

Bundle or set labels

If multiple items are sold as one unit, the package should make that clear. Bundle labels often include wording such as "Sold as Set" or "Do Not Separate." This helps prevent Amazon from separating items that should be sold together.

Warning labels

Some packaging requires warning labels. Poly bags may require suffocation warnings, and certain categories may need safety, expiration or compliance information. Requirements depend on product type, packaging and marketplace rules.

FNSKU Labeling Requirements

FNSKU labels are central to many Amazon FBA workflows. Sellers should treat them carefully because one wrong FNSKU can create inventory confusion.

Label the correct sellable unit

The FNSKU should be applied to the product or retail package that the customer receives. If the product is inside a box, the label usually goes on the outside of that box. If the product is inside a poly bag, the label should be on the bag and scannable without opening the package.

Make sure the barcode is scannable

Labels should be printed clearly with enough contrast. Avoid blurry printing, low-resolution files, wrinkles, curved surfaces, seams, corners or glossy material that makes scanning difficult. A prep team should test scanning before cartons are sealed.

Cover incorrect barcodes

If the product has a UPC, EAN or other barcode that Amazon should not scan, cover it with the FNSKU label or a blank sticker. Multiple visible barcodes can cause confusion during receiving.

Match the correct variation

Variations are a common source of labeling mistakes. A black medium product should not receive the label for a white large product. Before labeling, verify SKU, ASIN, color, size, model and package contents.

Use durable label material

Labels should stay attached during warehouse handling and international shipping. Poor adhesive, dusty packaging or humid storage conditions can cause labels to peel. When shipping from China, this matters because cartons may move through several handling points before Amazon receives them.

Carton Labeling Requirements

Carton labels help Amazon identify the shipment and receive boxes correctly. Even when each unit is labeled perfectly, carton labeling mistakes can delay inbound receiving.

Use the correct label for each carton

Each carton should receive the label generated for that carton in the shipment plan. Do not duplicate the same carton label across multiple boxes unless Amazon's workflow specifically provides that label structure.

Place labels on a flat surface

Labels should be placed on the outside of the carton, on a flat side, away from seams, corners and tape edges. The barcode should not be folded or wrapped around an edge.

Remove old shipping labels

If cartons are reused, old carrier labels, warehouse barcodes and supplier marks should be removed or covered. Extra barcodes can confuse scanning systems.

Protect labels during transit

Labels should not be placed where they will rub against pallets, straps or other cartons. If a label is damaged during freight, receiving can slow down.

Verify carton count

The number of cartons should match the shipment plan. A China prep warehouse should confirm carton count before pickup and document discrepancies.

Poly Bag and Suffocation Warning Labels

Poly bags are common in FBA prep, especially for apparel, accessories, small parts and products that need protection. Amazon has rules around bag thickness, closure, barcode visibility and suffocation warnings.

If a poly bag opening is above the relevant size threshold, a suffocation warning may be required. The warning should be visible and readable. Some sellers print warnings directly on the bag, while others apply a sticker.

The product barcode or FNSKU should be scannable through the bag or applied on the outside of the bag. The bag should be sealed so the product cannot fall out during handling.

Because rules can vary by marketplace and product type, sellers should confirm current requirements in Seller Central before production or prep. A prep partner can then apply the correct warning labels before shipment.

Bundle and Multipack Labeling

Bundles and multipacks create extra labeling risk because Amazon must understand that the package is one sellable unit.

Sold as set

If multiple products are sold together, the outside package should clearly state that the items are sold as one set. This prevents warehouse teams from separating the products.

One barcode for the bundle

The bundle should have one scannable FNSKU or barcode for the bundle listing. Individual component barcodes may need to be covered if they could be scanned by mistake.

Correct contents

Before labeling, verify that each bundle contains the correct items and quantities. A bundle with missing components can cause returns and negative reviews.

Strong packaging

The bundle package should hold all items securely. If the package opens during warehouse handling, Amazon may separate the components or mark the unit as unsellable.

Fyllhub can support FBA kitting and bundle preparation in China before products are shipped to Amazon.

Common Amazon FBA Labeling Mistakes

The same labeling problems appear again and again in FBA operations. Sellers can prevent many of them with a simple checklist.

Wrong FNSKU on the wrong product

This often happens when multiple variations are labeled at once. Separate SKUs physically before labeling and verify each label against a product sample.

Barcode covered by packaging

If the barcode is covered by wrap, tape or another label, Amazon may not scan it. Labels should be placed after final packaging when possible.

Old barcodes still visible

If old UPCs or supplier barcodes remain visible, Amazon may scan the wrong barcode. Cover or remove barcodes that should not be used.

Label placed on a curved surface

Curved bottles, tubes and irregular packages can make scanning difficult. Place labels on the flattest available surface.

Low-quality printing

Ink smears, low contrast and low-resolution files can make labels unscannable. Use reliable printers and test scans.

Carton labels mixed up

Carton labels should match the correct box. If carton contents vary by box, mixed labels can create receiving discrepancies.

Missing bundle warning

If a bundle is not marked clearly, Amazon may separate the items. Use "Sold as Set" or similar instructions when needed.

China-Based FBA Labeling Workflow

When products are sourced from China, labeling should fit into a broader prep and inspection workflow. A practical China-based process looks like this:

1. Supplier sends products to a China prep warehouse.

2. Warehouse receives cartons and checks quantities.

3. Products are inspected for visible defects and packaging issues.

4. SKUs and variations are separated.

5. FNSKU labels are printed and matched to each SKU.

6. Incorrect barcodes are covered.

7. Poly bag, warning, bundle or set labels are applied where needed.

8. Cartons are packed and carton labels are applied.

9. Carton count is verified against the shipment plan.

10. Inventory is shipped to Amazon FBA.

This workflow reduces the risk of labeling problems because labels are checked before international freight begins. If a supplier sent mixed variations or wrong packaging, the issue can be corrected in China rather than after the shipment reaches Amazon.

Fyllhub can connect labeling with Amazon FBA inspection, FBA consolidation and Amazon FBA shipping.

Amazon FBA Labeling Checklist

Use this checklist before approving a shipment:

• Each SKU has the correct FNSKU or barcode.
• Variations are separated before labeling.
• Each sellable unit has one correct scannable label.
• Old or irrelevant barcodes are covered.
• Labels are not placed on seams, corners or curved surfaces.
• Labels are printed clearly with strong contrast.
• Poly bags have required warnings.
• Bundles are labeled as sold together.
• Carton labels match the shipment plan.
• Carton count matches the shipping plan.
• Old carton labels are removed or covered.
• A final scan check is completed before pickup.

This checklist should be part of the prep warehouse workflow, not an afterthought.

For repeat shipments, keep the checklist as a standard operating procedure. Labeling quality improves when the same team follows the same sequence every time: receive, sort, verify, label, scan, pack, label cartons and approve pickup. This consistency is what prevents small errors from becoming expensive inbound delays.

Labeling for Different Sales Channels

Many ecommerce brands do not ship all inventory to Amazon. Some stock may be used for Shopify, WooCommerce, TikTok Shop, wholesale, replacement orders or crowdfunding backers. This creates a labeling challenge because different channels may need different packaging or barcodes.

A China fulfillment center can help separate inventory by channel. Units going to Amazon can receive FNSKU labels and FBA carton labels. Units held for Shopify or WooCommerce can use brand packaging, shipping labels and customer-facing inserts. This flexibility helps brands avoid applying Amazon-specific labels to every unit when only part of the stock is going to FBA.

See Fyllhub's China ecommerce fulfillment service if you need both Amazon and non-Amazon fulfillment from China.

How Fyllhub Helps With FBA Labeling

Fyllhub helps Amazon sellers prepare inventory in China before shipping to Amazon fulfillment centers. The team can receive products from suppliers, inspect inventory, apply FNSKU labels, cover incorrect barcodes, prepare bundles, verify carton labels and coordinate outbound shipping.

Fyllhub can support:

• FNSKU labeling
• Carton label application
• Poly bag and warning label prep
• Bundle and set labeling
• SKU sorting and variation checks
• Product inspection
• Kitting and packaging
• Supplier shipment consolidation
• China warehouse storage
• Shipping to Amazon FBA

This is useful for sellers who want one partner to manage the operational details between Chinese suppliers and Amazon warehouses.

FAQ

What is Amazon FBA labeling?

Amazon FBA labeling is the process of applying the correct barcodes and shipment labels to products and cartons before sending inventory to Amazon fulfillment centers. Labels help Amazon identify products, sellers and shipments.

What is an FNSKU label?

An FNSKU label is an Amazon barcode that identifies a product within Amazon's fulfillment network. It is commonly used to connect inventory to a seller's listing and account.

Do all Amazon FBA products need FNSKU labels?

Not all products need FNSKU labels. Some eligible products may use manufacturer barcodes, depending on Amazon settings and category rules. Many private label sellers still use FNSKU labels for clearer inventory control.

Where should I place an FBA label?

Place the label on the outside of the sellable unit or final retail package. The barcode should be flat, visible, scannable and not placed on seams, corners or curved surfaces.

Should old barcodes be covered?

Yes, if Amazon should not scan the old barcode. Covering irrelevant UPCs, EANs or supplier barcodes helps prevent scanning errors during receiving.

Can Fyllhub label Amazon FBA products in China?

Yes. Fyllhub can label Amazon FBA products in China, including FNSKU labels, carton labels, bundle labels and warning labels as part of a broader FBA prep workflow.

Final Thoughts

Amazon FBA labeling is not just an administrative step. It is a core part of inventory control, Amazon receiving and customer order accuracy. When labels are correct, Amazon can receive and fulfill inventory more smoothly. When labels are wrong, sellers can lose time, money and sales momentum.

For sellers sourcing from China, the best approach is to inspect and label products before international freight begins. This gives you a chance to fix supplier errors, verify barcodes, prepare cartons and ship compliant inventory to Amazon.

If you need help with labeling, inspection and prep, visit Fyllhub's Amazon FBA prep service or request a custom quote.