WIKI: Understanding Barcodes - UPC vs. Amazon FNSKU


Just starting an FBA business. Sorry but this post is confusing. I don’t understand still if we need BOTH a UPC Code and FNSKU code on the packaging?


@ssigal ,

You don’t need both. You can use one or the other.

P.S. If you can let me know what part of the post was confusing, I’ll edit it to try and make it more clear for others.


hey great info dax!

was just wondering:

if i get my manufacturer to make my own private label of 1 product and i plan to sell 500 units of that product, it will still have 1 UPC code correct?
my manufacturer is based in china and will have them ship to FBA so im wondering if this is the correct process in steps:

  1. have the manufacturer create a upc code unique to the product
  2. have them ship the product to FBA location in the states
  3. FBA will take care of the rest
  4. FBA will then be able to track inventory even though none of the units have a bar code on it

please let me know if this is correct as i dont wont to do anything stupid.



#4 is not correct. You must have either a UPC code or a FNSKU code on your product before it gets to FBA.

Sorry if that’s not clear - I’m happy to update the post if any particular part seems confusing.

As mentioned above, you can send inventory to Amazon with EITHER a UPC or FNSKU, but I generally recommend just using the FNSKU. With that in mind, this would be the process:

  1. Assign a UPC code to your product listing in Amazon.
  2. Go to your Manage Inventory page and click on the down arrow next to the Edit button for your product. You’ll see an option to Print Item Label. Click on that and you’ll have the option to save a PDF of the FNKSU code. This is what I send to my supplier to add on the packaging (or apply a sticker).
  3. Have them ship product to FBA location in the states.
  4. FBA will take care of the rest.

The process would be a little different if you wanted to use a UPC code instead, so let me know if that’s what you’d intend to do.


Wow this is some great info thanks jax!

So I need to create a listing for my item even before I send the units to fba.

After telling my supplier to create a UPC code for me I assign this UPC code to my item listed (or I can create a upc on my own correct?) which I don’t need to have them label it on my product

From here I follow your instructions on getting the fnksu number and have the supplier apply a sticker for each unit on my product (on label of each unit)

Also if I were to create a UPC code wouldn’t it be easier to get the supplier to apply a UPC code on the label as opposed to the fnksu number? Would like to know why specifically I would have them create a UPC code and then have them put on a fnksu number on each unit

Appreciate your help jax!


You don’t “create” a UPC code. You can purchase one online and just assign the number to your product.

The only reason you need a UPC code is because Amazon requires that every product has a unique identifier. So, even though it’s not printed on your packaging, you can’t create a new product listing on Amazon without one.

While the UPC code is specific to a PRODUCT only, the FNSKU code is specific to the PRODUCT AND SELLER. Your supplier doesn’t have to know what your UPC code is at all. So, from their perspective it shouldn’t be any easier to print the UPC code instead of the FNSKU (or vice versa). Either way, they will just be printing whatever barcode you give them.

I have a couple of recommended places to buy UPC codes here:


Hi Dax - Great answer BTW. Question: If I have my FNSKU printed on my package and someone else (hijacker) slaps their own FNSKU on it, can I claim that they’re selling a fraudulent item? Thanks.



Not exactly. In order to claim someone is selling a different item, it probably goes without saying that the products actually have to be different.

Another seller using their own FNSKU doesn’t mean anything by itself. All the FNSKU does is help Amazon keep track of which units of inventory were sent in by which seller. In other words, assume you and another seller are both selling the Webkinz Pup in the post example. Inventory from you and another seller might be exactly the same, but different FNSKU’s help Amazon know which units of inventory came from you and which came from the other seller.

However, this is only true for sellers that have elected to the disable Stickerless Commingled setting from their account. If both you and the other seller have enabled Stickerless Commingled, Amazon won’t differentiate between the inventory that was sent in.

Conversely, disabling Stickerless Commingled ensures that your inventory won’t get mixed up with that of another seller. So, for us as private sellers, this is important if you want to purchase something from a hijacker to ensure that they don’t have an genuine copy of your product. If it’s different, you can then contact Amazon to try and get the removed from the listing.

I know this is really confusing, so I hope the response made sense. Let me know if anything isn’t clear.


Thanks for your reply Dax. I do appreciate it.

Now I’m not sure if it’s still related to the topic per se but if another seller is selling my product (that they’ve purchased from me) using their own FNSKU, then technically the product is not ‘new’ then right? Can they claim it’s ‘brand new - unopened packaged’? As ‘new’ implies that all warranties and bonuses by the manufacturer (me) are valid when I obviously won’t offer in the case of a hijacker?


It would still be considered a brand new product, but the question would be whether or not it’s different than what you are currently selling. If they are not exactly the same, the other seller should create a new listing/ASIN to sell the product.

The question about your warranty depends on the terms you outlined. I think it’s reasonable to say that the warranty is valid only if purchased from an authorized retailer (you), but you’d probably want that to be made clear wherever the terms are posted. If it’s not explicitly mentioned, I think the expectation is that a customer should be entitled to the warranty if they purchased it new, regardless of who it was from. I’m not an attorney, but that’s how I view it.

I don’t know what other bonuses you bundle with the product, but you can make the claim that it’s a different product if the other seller doesn’t provide them.

That being said, Amazon doesn’t always enforce their own rules consistently. Sometimes they take action and sometimes they don’t.


Thanks Dax. Appreciate your time in replying to this.


Hi Dax,

Great articles! I have a quick question as I am planing to start selling bracelets on Amazon, and my bracelets will be of different color and size.
Will all models but of different size have the same FNSKU?
Please advise.

Thank you.


Yes. Each different variation will need its own FNSKU.

Also, you may already be aware of this, but it’s important to note
that Jewelry is a restricted category that requires approval before you can
offer an item. Make sure you are aware of all the requirements up front.


Thank you for your quick reply Dax.

To make sure I get this straight, same model different size, requires a FNSKU for each size?

Additionally, I purchased from a discount site some Branded Sunglasses at a good price and I was hoping to be able to sell them on Amazon, however since I am new and haven’t had any transactions yet, I would need to apply for an authorization to sell sunglasses, which I did but nobody replied yet, it’s been over 2 months now. Is there any other way I can list these branded sunglasses on Amazon?

Please advise.

Thank you.


[quote=“Dr.Creativity, post:23, topic:419”]
ake sure I get this straight, same model different size, requires a FNSKU for each size?[/quote]

Yes, you definitely need a unique FNSKU for each size. That’s the only way Amazon will be able to tell the difference between the variations.

Assuming the branded sunglasses you are trying to sell are listed in the Sunglasses category, you don’t have any other options to sell them on Amazon. Two months is a long time though. I would follow up. You could also consider using an ungating service if you have trouble getting approved on your own.


Hi Dax, thanks for the great article. There’s one thing I’m not 100% clear on though. I have a product I am manufacturing and selling myself, and I want to know if I should put a UPC or an FNSKU label on the product. You say:

you can send inventory to Amazon with EITHER a UPC or FNSKU

but in the article on commingled inventory you say:

I was forced to used Stickered Inventory even though I had already had my supplier print my UPC code onto the packaging. This means that I had to pay Amazon $0.20 per unit to label the products with an FNSKU for my first order and change my packaging later.

In my case my inventory will not be commingled so I want to put the right sticker on from the outset. It would be more convenient for me to use a barcoded UPC since I may ultimately use other (non-Amazon) channels. Is it the case that if you send non-commingled inventory to FBA with a barcoded UPC label that they will apply FNSKU labels at the $0.20 cost? Or is there a way to use UPCs for non-commingled inventory?

Any help is appreciated!


You’re right. The only way to have mon-commingled inventory is by using the
FNSKU. So, while you can ship inventory to the fulfillment centers with a
UPC code, Amazon will still apply the FNSKU and charge you 0.20 per unit.

There’s no way to have mon-commingled inventory without an FNSKU.


HI Dax,

I have one question I haven’t found anywhere.
Which one of these should I do first:
Create a listing and convert to FBA and get the FNSKU to have them printed on the packacking by the supplier ? or register the brand on Amazon?


I would create the listing first, but they are really completely separate


thank you very much :slight_smile: