Amazon has started passing back some inbound performance errors with a message of Unexpected items found in box.
This has happened both with sellers who use InventoryLab and those who do not. We have done some pretty extensive research over here regarding the causes. Below are our findings and ways to have the best chance at preventing the errors.
Cause #1 - Amazon Receiving Errors
In some cases, the problem lies fully on the Amazon receiving end. The box content information could be entered, sent, show as successful in Amazon's API (what 3rd parties use to communicate with Amazon), and you are still hit with this error! This will require you to open a case with Seller Support for help.
The good news is, there are a couple different ways to obtain proof of what was in your shipments so Amazon can get this corrected for you and remove your performance error. If you provide your Box Level Content in InventoryLab, you can print your packing lists. We would recommend doing this going forward if you are not currently since this has all of the items sent over with your box content, so you can see what information was sent over with the shipment and compare it to what Amazon shows.
If you do have these, you can send them over to Amazon so they can see what was sent and make the needed corrections. You can also print them retroactively from the Accounting > Inbound Shipping page. Just navigate to that page and click the shipment ID. You'll be able to print a packing list with images.
Note: If box contents was turned OFF for the shipment, you will not be able to print a packing list.
An alternative is to go to your Shipping Queue in Seller Central, where you can download the SKU List for each shipment to show what was in each shipment, specifically. This link is under the View Shipment button to the right side of your list of shipments. You can send this to Amazon as proof, as well.
Cause #2 - Not Correcting Feed Errors
Errors coming back from Amazon that we display in InventoryLab are not always being recognized or action is not being taken to correct them.
This results in having a failed feed - ie: Amazon did not get your box content data for any items in that feed.
In every case researched with this issue, the error was regarding an item or items that were missing required expiration dates. Since Amazon doesn't give us any specifics on what requires an expiration date at this time through their API system, we do recommend that if you are selling in categories where an item may need one to be hyper-aware of the Amazon Guidelines. We work hard to show you the errors as soon as they get kicked back to us.
While we cannot prevent you from hopping into Seller Central and completing your shipments prematurely, we have implemented a green notification that will pop up letting you know that your box content information has been successfully accepted by Amazon. If you do not received this message, your box content has not yet been accepted.
If InventoryLab presents an error to you, it is crucial that you correct the error and resend the Updated Box Content Information while your shipment is still in Working Status so that your data can be accepted and successfully received by Amazon.
The errors will appear usually within 60 seconds from the time you click the Transmit Boxes or Transmit All Boxes to Seller Central button on the Box Content page of your workflow and will pop up on your screen.
You can also view it by clicking on the List tab and selecting Amazon Listing Errors from the dropdown box.
The find the related error and click the i under the Action column for additional information
Unfortunately, Amazon does not usually provide to us which MSKU is the culprit. In the example above, however, it did. If you need help determining which item(s) require expiration dates, Amazon has a help article around Date- and Temperature-Sensitive Products. Seller Support should also be able to give you specifics if needed.
The Amazon List Errors page saves your errors for the last 30 days unless the x button to the far right of the error is clicked or the Reset button in the top right is clicked
Once you have found the MSKU(s) that are causing the trouble, you can alter or add the Expiration date by clicking the 3 horizontal lines to the right of the shipment under Working Shipments and selecting Box Content Information
Then, click directly on the expiration date (or N/A) and it will turn into an editable field to update
Once all of the needed changes have been made, click the Transmit Updated Boxes button in the lower right hand corner to resend your Box Content Data to Amazon.
Waiting once more for that update to go through and verify that no additional errors come back is highly recommended.
Cause #3 - Not Finishing the Full Workflow
If you begin your batch with Box Content feature turned ON, you must finish the entire batch workflow while your shipments are still in Working Status. Even if you only end up having a single box in your shipment, you had already indicated to Amazon at the start of your batch that you plan to send box content info - so now, they are expecting it!
After you have finished creating your shipments (Private Workflow) or have clicked the Review Batch page (Live Workflow), you will be on the Box Content Information page. This shows a list of your shipments for that batch and allows you to complete assigning your items to boxes.
You must assign all of your items to a box and click either the light orange Transmit Boxes button next to all of the shipments you intend to mail or click the Transmit All Boxes to Seller Central button to send all of the box content information for all of the shipments in 1 bulk feed.
It is important to note that if you use Transmit All Boxes to Seller Central, and an error occurs for any of the shipments in that feed, you must go back and resend the Updated Box Contents for all of the shipments. For this reason, unless you are 100% positive none of your items can possibly require an expiration date, we recommend using the Transmit Boxes button to send each shipment's data individually.
Once the feed has started the send process for all of your shipments listed, your batch will automatically close and you will be on the List->Closed Batches page.
If you do not finish the workflow, and complete your shipments prematurely inside of Seller Central, you will come back to a blank Box Content Information page (after a screen refresh) and it will be too late to enter them.
From here, there isn't much more you can do except manually close the batch in question to clear it from your Open Batches page and learn for next time. ☹️
To do this, hover over near the batch name on the left menu, and click the icon with three horizontal lines. This drops down to show you 2 icons. One is a Pencil (for editing the batch name) and the other is a Trash Can to close the batch.