Amazon rejects FBA shipments at receiving for three main reasons: packaging non-compliance (missing poly bags, incorrect labels, overweight cartons), labeling errors (wrong FNSKU, missing label, obscured barcode), or shipment plan discrepancies (more units than planned, wrong items).
When a rejection happens, Amazon typically posts a defect in the shipment status with a reason code. Review the reason code first — some are fixable with documentation, others require physical rework of the inventory.
If inventory is rejected and returned to you, send it to your 3PL for re-prep before re-submitting. Do not re-submit rejected inventory to Amazon without fixing the root cause — a second rejection compounds the problem.
The best prevention is a pre-shipment quality check at your prep center. Have the 3PL pull 10% of cartons for a spot check against the prep spec before carrier pickup. This catches systemic errors before they reach the FC.