Inventory reports answer different questions
A supplier purchase order, warehouse count, inbound record, and fulfillment-center report can all be correct while showing different quantities. Each represents a different location, status, or point in time.
Build a unit movement bridge
- Opening units by SKU and location.
- Supplier receipts and transfers into the shipping warehouse.
- Units shipped, received, available, reserved, or transferred by Amazon.
- Sales, customer returns, removals, disposals, damages, and adjustments.
- Closing units by status and the unresolved difference.
Use cut-off dates consistently
A unit shipped near month end may leave one location before appearing in another. Record in-transit inventory and use the same reporting cut-off across sources so timing differences do not look like shrinkage.
Investigate exceptions, not every line equally
Set quantity and value thresholds that trigger review. Document the explanation for resolved differences and carry only genuine open exceptions into the next period. This keeps the reconciliation focused and repeatable.