In a perfect Amazon world, the manufacturer barcode is all that's needed to send inventory to FBA warehouses. If you're reading this, you've probably figured out that's not the case. This is where the FNSKU barcode (Amazon barcode) comes in to play.
So, what exactly is an FNSKU barcode?
If an ASIN is a social security number for a UPC, then the FNSKU is a social security number for each individual SKU. There are certain products that will always require an FNSKU barcode (products with an expiration date, consumable products, topical products, and products that are prepped in a way that the barcode can not be scanned). In addition to these products, Amazon can deem any product to require an FNSKU as they see fit.
Why would Amazon require a product to have an FNSKU barcode?
It all comes down to them wanting the ability to trace a unit back to a seller. For instance, say I'm selling a pair of headphones on a listing with 10 other sellers (all using manufacturer barcodes / comingled inventory). A customer might buy a pair of headphones while "Seller Willy" has the buy box. The headphones that get picked from the bin might not have been sent to the warehouse from "Seller Willy". Once Amazon requires the ASIN to use an FNSKU barcode, they can pinpoint which seller has the defective headphones and act accordingly.
If an ASIN has not been deemed by Amazon to require an FNSKU, then the FNSKU value will simply match the ASIN and no additional labeling is required. This is the easiest and least expensive scenario.
If an ASIN has been deemed to require and FNSKU, then the FNSKU value will be different from the ASIN and unique to the individual SKU listed in your catalog. For example, "Seller Willy" wants to list a pencil (ASIN B071JM699P) and adds it to his catalog as SKU "pencil 1". Amazon has identified this as an ASIN that requires an FNSKU, so they assign a unique FNSKU (X0021B14QL) to SKU "pencil 1". Meanwhile, "Seller Rey" also wants to list this pencil (ASIN B071JM699P) and adds it to his catalog as SKU "awesomepencil2". Amazon then assigns an FNSKU (X0021AQ3HR) to "Seller Rey's" pencil SKU. Even though "Seller Willy" and "Seller Rey" have listed the same ASIN in their catalog, they both received different FNSKU's. These products are now uniquely tied to each seller.
The future of FNSKU barcodes.
I have been told by the seller central captive team that in the near future all SKU's will require a unique FNSKU label. I was told that this transition has already started and an email was sent out to all seller accounts with details about it. However, I have not been able to find said email on any of our accounts, so I can't 100% say this is true yet. Although, I have noticed a lot more SKU's being required to utilize the FNSKU barcode for our clients lately. I am still looking for an official statement from Amazon on this and will write a post if I find one.
Thank you for taking the time to read this post on the super exciting world of FNSKU's. If you have any questions please reach out to us any time. Happy selling!