An FBA shipment quantity discrepancy occurs when the number of units Amazon records as received doesn't match the quantity you expected Amazon to receive.
Before assuming inventory is missing, there are several things you should check.
1. Allow Amazon to Finish Receiving
Don't investigate a discrepancy while Amazon is still actively processing the shipment.
For multi-box or larger shipments, some units may be received before others. The received quantity can therefore change as Amazon continues processing.
2. Compare Expected and Received Quantities
Once receiving is complete, review the shipment in Seller Central.
Compare:
SKUs/FNSKUs
Expected quantities
Received quantities
Any discrepancies reported by Amazon
Identify exactly which products and quantities don't match.
3. Review Your Box Content
Compare Amazon's information with your own shipment records.
Check whether:
The correct quantity was packed.
The item was assigned to the correct box.
Box content information was submitted correctly.
The correct FNSKU was attached to the product.
An item may have accidentally been included in another box or shipment.
4. Check for Unexpected Units
A discrepancy isn't always a missing unit. Amazon may sometimes report a quantity different from what was expected, so review both shortages and unexpected quantities.
5. Check Whether the Shipment Can Be Investigated
Amazon controls when a shipment becomes eligible for investigation or reconciliation.
If Seller Central provides an option to investigate a discrepancy, follow the instructions shown for that shipment. Amazon may request supporting information or documentation.
6. Keep Shipment Records
Keeping accurate records makes discrepancies easier to investigate.
Useful records can include shipment details, box-content information, tracking information, product quantities, and other documentation associated with the shipment.