Quickly Fix the Stickerless Co-mingled Inventory Error in Seller Central

Something that I see come up often in Amazon FBA-related Facebook groups is the issue of not sending in inventory because of the dreaded Cannot be stickerless co-mingled message. I wanted to take a couple of minutes to discuss how to fix this with minimal struggle.

The root of the stickerless co-mingled problem

This only comes up when dealing with products marked as using the UPC to track the product. Called Co-mingled inventory, Amazon keeps track of exactly which item is yours, but only where your product is located. In other words, when they receive your co-mingled product, they place it somewhere in the warehouse that’s unique to your account.

When a customer orders a product, Amazon might not actually send them your unit(s) of that product, but rather a unit that’s closer to the customer. Since there’s no guarantee the product is actually any good, this can cause frustration and concern.

The good news and bad news: Amazon is moving away from this method. The percentage of ASINs that support co-mingled inventory is shrinking, and Amazon is pushing everyone to FNSKU-based tracking both at listing creation time (by only allowing for Amazon labels) or forcing listing adjustments. So the good news is inventory tracking is more precise. The bad news is, existing items or listings won’t play nicely with the change.

In reality, this isn’t actually a problem. Because co-mingled inventory tracking is prone to issues and isn’t as precise, FNSKU will eventually become the de facto method for 100% of the products in Amazon warehouses.

How FNSKU tracking works

When a listing is created and is set to use Amazon barcodes, a unique FNSKU number is generated. This number starts with an X and is incredibly unique. This number is attached and unique to the SKU, listing, ASIN, and Seller Central account. In other words, changing any one of those four variables results in a new FNSKU number.

Such tracking allows Amazon to determine which items in their warehouses belong to a particular seller without any doubt. This level of granularity also prevents other sellers’ potentially counterfeit or used-as-new inventory from being sent to your customers by mistake or intentionally. Your customer will only ever receive your inventory, and the state of said inventory is entirely your responsibility.

Fixing the stickerless co-mingled error

The solution to the problem is actually in the message Amazon provides and contrary to anything else you might see out there the only way. To clear this up, the listing will need to be deleted and re-created. Existing listings/SKUs cannot be converted on the spot (for the same reason I described earlier about combining data sources to create the inventory association).

In other words, delete the existing listing and create a new one. This will create a bit of duplication in 3rd-party tools like a repricer or inventory tracker. Normally I recommend using the same SKU when recreating a listing, but in this case, it’s likely safer to have a new one generated (or define it on your own).

If the inventory is still present, open a case with Seller Central Support and ask that they pull the inventory and run it through the FBA labeling process. You’ll have varying degrees of success with this one and may have to jump a couple of hurdles to get them to understand what you’re asking for fully, but it should be possible. Otherwise, recall the inventory and re-send it with Amazon labels attached that match the new listing.

Preparing for the future

Now is also a good time to ensure your account is always set to use the Amazon barcode for all new listings. Log in to Seller Central and head to Settings > Fulfillment by Amazon. Look for the “FBA Product Barcode Preference” section. If it’s not set to “Amazon barcode,” click Edit and update the option appropriately. Print your FNSKU labels and apply them to your items.

You’re now good to go!

Last Updated: August, 24th, 2021 at 12:39 am UTC
Johnathan Lyman

Johnathan Lyman



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