Problem
Amazon inventory mismatch
Why Amazon FBA or seller-fulfilled counts diverge from warehouse and Shopify, how to diagnose it, and how AXIOTRA measures potential exposure.
What it is
Amazon reports a different available quantity than warehouse or Shopify for the same resolved SKU. The mismatch may be reserved units, inbound shipments, stranded inventory, or a mapping error between FNSKU and your SKU.
How it happens
FBA inbound not yet checkable, unreconciled customer returns, damaged disposition, or a listing that maps two SKUs onto one FNSKU. Late SP-API inventory snapshots make it look like drift when it is lag.
Why it matters
Oversell produces refunds and account health hits. Undersell hides GMV. Potential exposure is abs(delta units) × contribution margin when COGS is known; otherwise UNKNOWN.
How to diagnose
Pull the ledger for the SKU. Compare warehouse on_hand, Amazon available, reserved, inbound. Check entity mapping confidence. If mapping is not exact, do not merge.
How AXIOTRA detects it
The inventory divergence detector reconstructs expected available from events and diffs each source snapshot. Evidence includes the formula, timestamps and external ids.