EDI 856 Ship Notice (ASN): What Retailers Actually Require

If there’s one EDI transaction that causes more pain than any other, it’s the 856 Ship Notice. Retailers have strict requirements, the hierarchy is unforgiving, and getting it wrong doesn’t just cause a failed transaction — it triggers chargebacks.

What Is an EDI 856?

The 856 is your advance ship notice — you send it when you ship an order. It tells the retailer:

What’s in the shipment (items, quantities)
How it’s packaged (cartons, pallets)
When it shipped and when it will arrive
The tracking/PRO number

Retailers use the 856 to plan receiving, pre-assign dock doors, and verify your shipment matches the PO before it arrives. A missing or malformed 856 means a slower receiving process — and chargebacks.

The Hierarchy Is Everything

The 856 uses an HL (Hierarchical Level) loop structure to represent the physical structure of the shipment:

S — Shipment
  O — Order
    P — Pack (Pallet)
      T — Tray / Inner Pack
        I — Item

Not every level is required by every retailer, but the order matters. Walmart requires S > O > P > I (Shipment, Order, Pack, Item). Each level gets its own HL segment with a parent reference back to the level above it.

Getting the hierarchy wrong — wrong HL codes, missing parent references, wrong nesting order — will cause hard rejections.

Key Segments

BSN — Beginning Segment for Ship Notice

BSN01: Transaction Set Purpose (00 = original, 05 = replace)
BSN02: Shipment Identification Number (your shipment ID)
BSN03: Date
BSN04: Time
BSN05: Hierarchical Structure Code — this tells Walmart exactly which HL levels you’re using

HL — Hierarchical Level One per packaging level. HL01 is the ID, HL02 is the parent ID, HL03 is the level code.

TD1 — Carrier Details Packaging code, weight, dimensions. Required for most retailers. Walmart will charge back for missing or wrong weights.

TD5 — Carrier Details (Transportation) SCAC code, carrier routing, PRO/tracking number.

PRF — Purchase Order Reference Links the ship notice back to the original PO. PO number must match exactly.

LIN — Item Identification UPC, GTIN, buyer’s item number. One LIN per item line. Must match what’s in the 850.

SN1 — Item Detail (Shipment) Quantity shipped, unit of measure. This is how you tell the retailer exactly what you sent.

The Carton Label Connection

The 856 and your UCC-128 carton labels must match. The SSCC-18 barcode on each carton needs to appear in your 856 in the TD3 or MAN segment. Retailers scan labels at receiving and reconcile against the 856. If your SSCC-18s don’t match, the shipment gets flagged.

Generate your SSCC-18s before you build the 856 so you can populate both correctly.

Walmart-Specific Requirements

Walmart’s 856 spec is one of the more demanding:

Ship within the window — your 856 ship date must fall within the PO’s ship window
Carton-level detail required — every carton needs its own HL T loop
Weight/dims mandatory — TD1 weight and dimensions required or you get a chargeback
Timing — must be sent same day as physical shipment, not after

Walmart’s compliance program tracks your ASN accuracy rate. Consistently bad 856s affect your supplier scorecard.

Common Errors

HL parent reference wrong — HL02 must point to the correct parent HL01 value
PRF01 doesn’t match PO number — exact match required, including leading zeros
SN102 unit of measure wrong — must match the unit Walmart uses, not what you use internally
Missing MAN segment — SSCC-18 barcode missing from carton-level HL loop
BSN05 wrong — hierarchical structure code doesn’t match the HL levels in the document

The 856 is complex enough that most suppliers see multiple rounds of certification failures before getting it right. If you’re fighting it, talk to TebcoForge. We’ve built 856 maps for all major retailers and know exactly where the bodies are buried.