Amazon FBA

To sell products through Fulfillment by Amazon (FBA), each item you list requires a unique Amazon FNSKU code. This guide explains what FNSKUs are, why they are essential for FBA, and step-by-step instructions for generating and applying FNSKUs to your products.

What is an Amazon FNSKU?

FNSKU stands for “Fulfillment Network Stock Keeping Unit” code. It is a unique identification number that Amazon assigns to each product a seller lists on Amazon.

Some key facts about FNSKUs:

  • Alphanumeric code with 14 characters, like “X000DXM9O3A4ZT”
  • Used to identify products fulfilled through FBA
  • Scannable barcode encoding the FNSKU
  • Required for inventory tracking and order fulfillment
  • Needed for commingling inventory in FBA

FNSKUs allow Amazon to manage and ship each seller’s inventory efficiently from their collective warehouses.

Why Do Products Need FNSKUs for FBA?

There are a few crucial reasons every FBA product needs its own FNSKU:

Inventory Tracking

FNSKUs enable Amazon to accurately track which seller owns each item as products are distributed across fulfillment centers.

Order Fulfillment

When an order comes in, Amazon scans the FNSKU to determine which seller’s inventory to pull from to fulfill the order.

Commingling Eligibility

Having a FNSKU is required for items to be commingled together with other sellers’ inventory.

Product Identification

FNSKUs allow Amazon to identify issues with specific products like defects, safety reports, expiration dates etc.

Unique IDs

Prevents duplicate listing issues since each product variation gets a distinct FNSKU.

FNSKUs are essential for Amazon’s ability to store inventory from many sellers together and pull the correct units to fulfill orders quickly and accurately.

FNSKU Requirements

Barcode Standards

For FBA products, Amazon requires scannable barcoded FNSKU labels. Here are standards:

  • Code 39 barcode symbology
  • FNSKU in uppercase without spaces
  • Barcode at least 15mm tall, readable at arms length
  • High quality black ink on white background

Label Size and Placement

  • Minimum of 1.88 X 1.25 inches
  • Applied flat on largest product surface
  • Leave “quiet space” around barcode

One FNSKU per Item

  • Each unique product must have its own FNSKU
  • Variations of color, size, etc need separate FNSKUs

GTIN Exemption

  • FNSKU labels exempt items from needing GTIN/UPC codes

Following Amazon’s labeling standards ensures barcodes are scannable throughout the fulfillment process.

Getting FNSKUs for Your Products

There are two ways sellers can get FNSKUs for their Amazon products:

1. Manufacturer Barcodes

If your products already come labeled from the manufacturer with a scannable barcode, you can “Request FNSKU” in Seller Central. Amazon will generate the FNSKU barcode with embedded code.

2. Apply FNSKU Labels

For unlabeled products, generate FNSKU stickers in Seller Central to print and apply.

We’ll cover the specific steps for each method next.

Method 1 – Requesting FNSKU Barcodes

For products with existing barcodes, follow this process:

Step 1 – Submit Barcode Image

In your Seller Central inventory, use the “Request FNSKU” function. Submit a clear image of the manufacturer barcode.

Step 2 – Amazon Review

Amazon will review the barcode image to ensure it meets standards. May take 24-48 hours.

Step 3 – Amazon Generates FNSKU

Once approved, Amazon will email your FNSKU barcodes containing the embedded product codes.

Step 4 – Print and Apply

Print the barcode images on labels. Apply over the manufacturer barcode, lined up correctly.

This overlays the Amazon FNSKU barcode preserving the original UPC/EAN. Fast and easy!

Method 2 – Create and Apply FNSKU Labels

For products without existing barcodes, generate custom FNSKU labels:

Step 1 – Create New Product Listing

In Seller Central, create a new product listing for the item. Leave a default sku for now.

Step 2 – Generate FNSKU

Navigate to “Print Labels” for your listing. Select “Generate FNSKU”. Amazon will create the new FNSKU.

Step 3 – Print Label

Amazon will generate a printable label with FNSKU barcode. Print onto label stock using a high-quality printer.

Step 4 – Apply Label

Carefully apply the label flat on the largest face of the product following Amazon’s guidelines.

With this method you create original FNSKUs right on the label. Simple for unlabeled products.

Where to Place FNSKU Labels

Amazon has specific recommendations on label placement:

Consistent Location

All products should have FNSKU labels applied in the same relative location and orientation for easy scanning.

Largest Flat Surface

Apply label to the largest flat surface – typically the front or back.

Avoid Edges or Curves

Don’t wrap around curved surfaces or place close to edges. Must lay completely flat.

Consider Model Number

If possible, avoid covering any important model numbers printed on product.

Leave Quiet Space

Leave some blank “quiet space” around barcode for unobstructed scanning. Margins of at least 0.25 inches.

Following these guidelines ensures your items are scannable throughout FBA processing and order fulfillment without issues.

Managing FNSKUs for Product Variations

For products with multiple variations like colors, sizes etc each requires its own FNSKU:

  • Create separate product listings for each variation.
  • Generate a unique FNSKU for each through “Print Labels”.
  • Include the variation specifics in the product title and description.
  • Use clear labeling like “Red” “Size 10” on product to match FNSKU listing details.
  • Store same items together when shipping to FBA but label variations to keep organized.

Proper labeling and matching FNSKUs to variations helps Amazon fulfill the correct items to buyers.

Can I Reuse FNSKUs?

Sellers cannot reuse FNSKUs. Each unique product must have its own code. However:

  • Unchanged new inventory added in the same batch size can use same FNSKU.
  • Resending unsold inventory that was returned uses the original FNSKU again.
  • Minor product revisions may allow reusing FNSKU – ask Amazon first.

FNSKUs can’t be reused for entirely new products to prevent mismatches. But applicable for replenishing existing products.

Printing Your Own FNSKU Labels

While Amazon provides FNSKU labels, many sellers prefer printing their own. Benefits:

  • Add your own branding like logo, designs, and colors
  • Include additional product and seller details
  • Use special label materials for enhanced durability or aesthetics
  • Save costs associated with purchasing labels from Amazon

When printing your own, ensure barcodes meet Amazon’s scannability standards. FNSKUs must be uppercase, embedded correctly, and unobstructed on the label.

Key FNSKU Best Practices

Follow these tips for smooth FNSKU generation and labeling:

  • Double check label quality and code accuracy before applying. Reject unclear printouts.
  • Align barcode neatly within label margins to avoid cutting off edges.
  • Ensure product identifiers like manufacturer SKU or UPC match FNSKU details.
  • Apply labels on a flat surface like a table to prevent creasing and bubbles.
  • Consider clear poly bagging to protect labels on items prone to marking.
  • Store backup copies of FNSKU barcodes digitally for reference.

Proper labeling technique ensures scannability, avoids errors, and prevents inventory issues down the chain.

Can I Sell FBA Without FNSKUs?

FNSKUs are mandatory for all FBA products. Amazon will not let you list or ship items to their fulfillment centers without providing FNSKUs.

The only exception is products using Amazon’s commingling SKU system which assigns a shared ASIN and does not require unique FNSKUs. However, commingling inventory has significant downsides like counterfeit risk.

Using FNSKUs, while adding some work initially, provides major benefits around inventory tracking and sales attribution.

Troubleshooting Issues With FNSKUs

Here are tips for resolving common FNSKU problems:

FNSKU Already Exists

If Amazon says the FNSKU is already in use, the same code was erroneously generated twice. Delete one listing and generate a new FNSKU.

Missing or Unscannable Labels

Double check all items have scannable FNSKU labels before shipping. Regenerate and relabel anything missing.

Mismatch With Product

Make sure each FNSKU precisely matches the product details like title, color, size etc to prevent mismatches.

Duplicate Listings

Using the same FNSKU on multiple listings of the exact same product. Consolidate into one listing.

Inventory or Sales Issues

If noticing odd inventory counts or sales attribution – ensure FNSKUs correctly assigned and labels remain intact.

Routinely inspecting and auditing FNSKUs as part of your FBA prep avoids snags during fulfillment.

FNSKU Listing Changes

If you need to edit your product listing after creating the FNSKU:

  • Can edit title, description, price and images without changing FNSKU
  • Changing primary category or product identity requires new FNSKU
  • Editing Parent SKU relationship to variants also needs new FNSKU

Minor updates don’t affect FNSKU. But substantial changes require generating a new code to prevent mismatches. You can ask Amazon Seller Support for guidance on any specific listing update.

FNSKU Removal and Disposal

If you need to remove an FNSKU from listing, like discontinuing a product, follow Amazon’s process:

  • Delete the listing from Inventory > Manage FBA Inventory.
  • On the removal order, select “Dispose” for items in FBA or Amazon will return them.
  • Amazon will dispose of items not meeting saleable condition requirements.
  • You’re charged disposal fees based on units and size.

It’s important to fully delete discontinued listings and disposed of poor condition inventory to avoid storage fees accumulating or causing shipment issues.


Here are answers to some frequently asked questions about Amazon FNSKUs:

Do FBA shipments to Amazon need FNSKUs before sending inventory?

Yes. Any inventory sent into FBA must have scannable, compliant FNSKU labels applied to each unit before shipping.

Can I purchase pre-made FNSKU labels from Amazon?

Yes, Amazon offers pre-printed labels for purchase on demand, but most sellers prefer printing their own using label sheets and thermal printers.

Can I sell products on Amazon without using FBA and FNSKUs?

Yes. Selling merchant fulfilled requires UPC/EAN codes instead of FNSKUs. No FNSKUs needed unless using FBA fulfillment.

Do Amazon FNSKUs expire?

No, FNSKUs remain assigned to your products indefinitely. They only expire if you delete the product listing.

Can I apply FNSKUs over an existing UPC barcode?

Yes, Amazon’s FNSKU barcodes can be printed and applied directly over your UPC barcode on the packaging.

Bottom Line

The key points to remember about Amazon FNSKUs:

  • Required unique codes for inventory tracking in FBA
  • Scannable barcode containing 14 digit alphanumeric identifier
  • Two options: use existing UPC or generate FNSKU labels
  • New FNSKU needed for each product variation
  • Must meet Amazon’s barcode standards and placement guidelines
  • Crucial for commingling eligibility and proper order fulfillment

While creating and applying FNSKUs adds some work, it enables the efficiencies and benefits of Fulfillment by Amazon. Use this guide to master FNSKUs for smooth selling!


  • Gio Watts

    Gio Watts brings over 10 years of digital marketing experience to his role as marketing manager at Walletminded. In his current position, Gio oversees brand marketing, campaign management, and audience growth initiatives. Prior to joining Walletminded, Gio held marketing roles at several ecommerce and SaaS startups, most recently serving as senior marketing manager at CloudTable Inc. There, he specialized in paid social advertising and content marketing. Gio holds a bachelor’s degree in business marketing from the University of Oregon. He is a certified content marketing specialist and frequently guest lectures at his alma mater. When he's not devising omni-channel marketing campaigns, you can find Gio coaching youth basketball and indulging his passion for live music.

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