# Shipment Sentry

> Independent Amazon Vendor shipment preflight for X12 856 and Vendor Shipments API JSON. Not affiliated with or endorsed by Amazon.

## Primary resources

- [Free 856 and API validator](https://www.shipmentsentry.com/tools/amazon-edi-856-validator): Run a preflight with exact locations, sources, and rule-pack versions.
- [Pricing](https://www.shipmentsentry.com/pricing): Free, Pro, Team, and one-time readiness audit.
- [ASN readiness audit](https://www.shipmentsentry.com/amazon-asn-audit): Human-reviewed implementation evidence.

## Guides

- [Amazon EDI 856, checked against the shipment—not just the syntax](https://www.shipmentsentry.com/amazon-edi-856): The EDI 856 is an advance ship notice. For an Amazon Vendor shipment, it communicates shipment identity, timing, transport references, purchase orders, packaging hierarchy, items, quantities, and container identifiers. A useful preflight checks the X12 envelope and HL tree, then applies Amazon-documented shipment rules and flags anything that still depends on the vendor account’s current implementation guide.
- [Amazon ASN errors, translated into an exact fix](https://www.shipmentsentry.com/amazon-asn-errors): The fastest way to diagnose an Amazon ASN problem is to separate four layers: X12/JSON parsing, envelope or schema validity, shipment hierarchy and identifiers, then reconciliation with the physical pack and purchase order. Fix the first blocking layer, run the preflight again, and only then investigate account-specific rules.
- [Receive Accuracy starts before the truck leaves](https://www.shipmentsentry.com/amazon-receive-accuracy): A preflight can reduce preventable Receive Accuracy problems by checking whether the shipment confirmation is internally valid and reconciling it with purchase orders, pack output, carton or pallet counts, SSCC labels, item quantities, and transportation references. It cannot predict every fulfillment-center observation, so physical receiving evidence and Vendor Central records still matter.
- [Check the SSCC before it reaches the carton label and ASN](https://www.shipmentsentry.com/amazon-sscc-label-requirements): An SSCC is an 18-digit GS1 identifier for a logistics unit. The final digit is a calculated check digit. Amazon’s public shipment-confirmation guidance says the SSCC must be unique, not reused within 365 days, and represented on both the physical barcode label and shipment confirmation. It also describes adding the GS1 Application Identifier 00 when implementing GS1-128.
- [Multi-PO pallet ASN hierarchy without the guesswork](https://www.shipmentsentry.com/amazon-multi-po-pallet-asn): A common multi-PO pallet 856 pattern is SOTPI: Shipment → Order → Tare (pallet) → Pack (carton) → Item. Each HL01 must be unique, every HL02 must reference an earlier parent, and each carton and item must remain connected to the correct purchase order. Confirm the exact profile in the current Vendor Central implementation guide for your account.
- [Vendor Shipments API payloads, preflighted before the 202 response](https://www.shipmentsentry.com/amazon-vendor-shipments-api): The Vendor Retail Procurement Shipments API exchanges shipment documents for Amazon vendors. SubmitShipmentConfirmations accepts a request containing one or more shipment confirmation objects. The current public model requires party, identifier, confirmation date, type, and shipped-item data; Amazon’s tutorial adds operational rules such as pre-receipt timing, BOL requirements for FTL/LTL, small-parcel carton confirmation, and SSCC handling.
- [Test the shipment failures your happy-path 856 never shows](https://www.shipmentsentry.com/amazon-edi-testing): An Amazon Vendor 856 test plan should cover X12 envelope controls, every supported hierarchy and shipment type, required references, item and quantity boundaries, SSCC labels, multi-PO packing, replacements, duplicate/retry behavior, acknowledgements, and reconciliation to warehouse source data. Run accepted and rejected fixtures automatically on every rules or mapping change.

## Data and citation policy

Each validator finding declares its evidence class: current Amazon public documentation, X12 base structure, GS1, or account-specific warning. Raw shipment content is not retained by default. Current Vendor Central documentation remains controlling.

Last reviewed: 2026-07-16. Rule pack: 2026.07.16.