What is an FNSKU?
The Amazon FNSKU, or Amazon Fulfillment Network Stock Keeping Unit, is a unique identifier Amazon assigns to your product. It allows Amazon’s fulfillment centers to easily manage and track FBA inventory for Amazon sellers.
When sellers list their items on Amazon, they provide information such as the item’s title, price, and product category. Amazon then assigns the product with an FNSKU barcode so that it can better track and manage inventory. Sellers can then download FNSKU labels that can be applied to individual units and act as the product’s barcode in replace of a manufacturer’s barcode.
Understanding the Amazon FNSKU
If you’re sending products to an Amazon FBA warehouse, they must be labeled correctly with either an Amazon FNSKU or a manufacturer’s barcode.
But what’s the difference? What is an Amazon FNSKU? And how do you create one? And where do you put it??
So many questions! But luckily, we’ve got all the answers for you right here.
Amazon FNSKU barcode vs manufacturer barcode
When creating a new listing on Amazon, you can choose to use the manufacturer’s barcode or the Amazon barcode.
The Amazon barcode is the FNSKU, which we will show you how to create and download shortly.
The manufacturer’s barcode, however, is a barcode applied by the brand owner. If you are selling other brand’s products, this will already be taken care of, and any product should already have this on
However, if you are a private label seller, you will need to decide whether to use FNSKU labels or a manufacturer’s barcode.
We would generally recommend using an FNSKU label as it does have its distinct advantages – we’ll cover those shortly in the pros and cons
However, if you do decide to use a manufacturer barcode instead of an FNSKU label you will need to generate a barcode from a UPC or EAN number.
UPC vs FNSKU
A UPC is a 12-digit Universal Product Code that is assigned to products at the manufacturer level.
This means that if you’re private labeling products, you will need to assign a UPC number to each product you sell.
Amazon requires sellers to use official GS1 UPC numbers rather than recycled numbers previously assigned to another business.
Once you assign a UPC number to a product, you can create a UPC barcode image using that number and either apply the barcode to the product with a sticker or embed it into your packaging design.
The UPC barcode will then be the barcode Amazon fulfillment centers scan when your products arrive rather than the FNSKU label.
You can only have one barcode per product – if you choose the manufacturer barcode option you don’t need an FNSKU label, and vice-versa.
EAN vs FNSKU
An EAN is a 13-digit European Article Number used in Europe, the Middle East, and Asia.
This is similar to a UPC but has an extra number at the beginning of it.
An EAN functions exactly the same as a UPC code but is simply a version used by other countries.
ASIN vs FNSKU
An ASIN is an Amazon Standard Identification Number—a ten-digit code made up of numbers and letters that Amazon assigns to products sold on Amazon.
This is different from a UPC or EAN number as it is unique and only used for Amazon listings.
This means that if you have different variations of the same product (different sizes, colors, etc.), each variation will need a separate ASIN, as no two listings can have the same ASIN.
Each FNSKU label will show the ASIN on it, but the two are separate product identifiers.
SKU vs FNSKU
As you can probably guess, SKU and FNSKU are very similar.
Whereas an FNSKU is a Fulfillment Network Stock Keeping Unit, an SKU is simply a Stock Keeping Unit.
An SKU is a code that Amazon sellers assign to their products. This helps them better track and manage inventory across multiple marketplaces.
If you don’t assign products an SKU when creating a listing on Amazon, one will be automatically generated for you. So it’s best to plan your SKU structure ahead of time.
Do you have to create an Amazon FNSKU for your product?
No, you won’t be forced to use the FNSKU for your FBA inventory in most cases.
On rare occasions, you may be required to do so, such as when selling some consumable products.
But for the most part, you can decide which barcode to use.
How do you create an Amazon FNSKU?
Creating and applying Amazon FNSKUs is a relatively simple process.
Creating FNSKU labels
All you need to do is log in to Amazon Seller Central and click on Inventory > Manage Inventory.
Next to the product you want to generate the FNSKU label for, click the drop-down arrow next to the edit button.
Here, you’ll see a ‘Print labels’ option.
Click this and Amazon will give you the option to enter the number of labels needed.
Applying FNSKU labels
If you are going to print labels in order to apply to each unit with a sticker, enter the total number of units you’re sending into the Amazon fulfillment center.
Then you’ll need to download the PDF file, print item labels and manually apply to each individual unit – not just outer cartons like you would FBA shipment ID labels.
Private label sellers are better off downloading a single FNSKU barcode and embedding that into a product’s box packaging design where the manufacturer’s barcode would typically go. This has the benefits of saving a lot of time for you or your supplier in manually labeling each unit and it also looks a lot more professional.
Does the FNSKU go on master cartons?
No, you only need to print FNSKU labels on the individual units. Instead, you should apply a shipping label to your master cartons.
If you are shipping directly to Amazon FBA from your supplier, create a shipping plan on Amazon seller central. The shipment creation workflow will create an FBA shipment ID label for you to apply.
When should you use an Amazon FNSKU?
Our recommendation is that wholesale, arbitrage, and private label sellers using the FBA program all use an FNSKU to keep better track of inventory.
Sellers using the FBM (fulfilled by merchant) method won’t be using the Amazon fulfillment process, so they don’t need to use an FNSKU. Instead, they should stick to the manufacturer’s barcode.
The pros of using an FNSKU barcode
The FNSKU code is a popular choice for many sellers for one main reason, but there’s another benefit.
Avoid commingled stock
The first and most significant benefit of using Amazon barcodes is that they ensure Amazon tracks your specific items within its fulfillment process, meaning you avoid commingling (mixing up) stock with other sellers.
Commingling is when multiple sellers stock the same product with the same manufacturer barcode in an Amazon fulfillment center.
The commingled inventory is stored in the same pick-and-pack bins, and units from either seller can be used to fulfill either seller’s orders.
This is generally not a problem for wholesale sellers or those operating an arbitrage business model.
But for private label brand owners, this can cause issues if a bad actor sends counterfeit products in using the same manufacturer’s barcode.
Using an FNSKU avoids this issue and is the number one reason why it is our recommended course of action.
Save money on barcode images
A supplemental benefit is that FNSKUs are free. Whilst you will still need to pay for and assign a UPC or EAN number to your product, you won’t need to produce a scannable barcode image.
GS1 charges extra for producing barcode images, and using an FNSKU will also save on these costs.
The cons of using an FNSKU barcode
There is only one minor downside to using an Amazon label on your products.
An FNSKU can’t be used for retail
If you’re looking to grow a private label brand and perhaps one day sell your products in brick-and-mortar retail stores, you won’t be able to use an FNSKU as your ID label.
In this scenario, you’d need to use a manufacturer’s barcode.
A solution here, though, would be to add specific product labels with an FNSKU when shipping products into FBA.
In Summary
As you can see, the pros of using FNSKUs far outweigh the cons, and Amazon makes it relatively easy to print item labels with its in-built system.
By using Amazon FNSKUs, Amazon sellers can benefit from better inventory control across multiple marketplaces and avoid a host of potential issues arising from commingled inventory.
