How ASN Tracking Works: EDI 856, SSCC Labels, and Retail Receiving

When a truck pulls up to a distribution center, the receiving team already knows what is on it: which purchase orders it carries, how many pallets and cartons are inside, and which items sit in each carton. Nobody opens a box to find out. That advance knowledge comes from the Advance Ship Notice, and the way it links electronic data to physical freight is what people mean by ASN tracking.

For suppliers, ASN tracking is more than a logistics convenience. It is the record retailers use to receive your goods, match your invoice, and decide whether to pay in full. When the ASN tracks the shipment accurately, receiving is fast and payment follows. When it doesn't, the gap turns into shortage claims and compliance fines.

What Is an Advance Ship Notice (ASN)?

An Advance Ship Notice (ASN) is an electronic document a supplier sends to a buyer before a shipment arrives, describing exactly what is shipping and how it is packed. In the X12 EDI standard, it is the EDI 856 transaction set.

An ASN typically includes shipment details such as ship date, carrier, and tracking; order information such as PO number and ship-to location; the packaging hierarchy of pallets and cartons; item-level SKU, UPC, and quantity data; and SSCC barcode numbers.

It is sent after the supplier confirms what is shipping, usually at or shortly after shipment, and before the goods reach the buyer's receiving location.

ASN vs. Tracking Number: What's the Difference?

ASN tracking and carrier tracking answer different questions. Carrier tracking tells you where a shipment is. ASN tracking tells the receiver what is inside it and where each unit belongs.

The ASN is the only one of these that arrives before the shipment, details carton-level contents linked to SSCC barcodes, and does so in a machine-readable format. It often carries the carrier tracking number too, so the two work together.

EDI 856 ASN Hierarchy: Shipment, Order, Pack, and Item Levels

ASN tracking works because the 856 describes a shipment the way it is physically built. Rather than a flat list, the ASN describes a nested tree that mirrors how the shipment is organized.

This arrangement is most commonly called SOPI, for Shipment, Order, Pack, Item, with a tare level added when pallets are tracked separately. The hierarchy tells the receiving dock what is on the truck, which carton holds which SKU, and how each carton maps back to the purchase order.

Retailers set their own requirements within this structure. One may require carton-level detail while another requires pallet-level hierarchy, SSCC labels, department references, or specific carrier codes.

Can One ASN Cover Multiple POs or Split Shipments?

Yes, when the POs travel on the same truck to the same destination. The ASN carries one order level for each PO, with that PO's pallets, cartons, and items nested beneath it.

The reverse also applies. When a single PO is split across multiple trailers, each trailer needs its own ASN with a unique document ID. Sending one ASN for a split PO leaves the second trailer arriving with no matching record.

Completeness matters at the PO level too. Walmart requires every line on the purchase order to be included in the ASN, so an ASN that skips PO lines fails accuracy checks.

How SSCC-18 Labels Link the ASN to Physical Freight

The Serial Shipping Container Code (SSCC-18) is what makes ASN tracking possible. Each carton or pallet gets a unique SSCC number, printed on a GS1-128 label and included in the ASN's MAN segment. The number exists in two places at once: on the physical label and in the electronic record.

At the dock, the receiving system reads that number and looks it up. The receiving clerk scans the SSCC on a carton, the system reads the pack-level entry, and the item-level entries tell it exactly what units to expect inside.

For pallets, one scan replaces dozens. Using the SSCC allows a single barcode scan per pallet and removes the need to scan multiple barcodes during receiving.

How ASN Tracking Works: 9 Steps From PO to Payment

ASN tracking follows the shipment from the supplier's dock to the retailer's payment system.

1. The retailer sends a purchase order: the EDI 850 sets the items, quantities, and delivery location
   
2. The supplier picks and packs: each carton and pallet receives an SSCC-18 label
   
3. The supplier builds the ASN: shipment, order, pack, and item data are compiled, ideally generated automatically from the WMS or ERP
   
4. The ASN is transmitted: usually right after labels print and before the trailer arrives at the retailer
   
5. The retailer acknowledges it: the retailer returns an EDI 997 functional acknowledgment, and business rule errors come back on an EDI 824 application advice
   
6. The retailer plans receiving: ASN data sets dock appointments, labor, and cross-dock decisions before the truck arrives
   
7. The shipment is scanned at receiving: each SSCC is matched to the ASN, and discrepancies are flagged on the spot
   
8. Receipts are recorded: what was scanned becomes the official received quantity
   
9. The invoice is matched: the EDI 810 is compared against the PO and the receipt, and any gap becomes a deduction

The sequence matters. The typical order is 850 order, 855 acknowledgment, 856 ship notice, then 810 invoice. If the ASN is late or wrong, steps 6 through 9 all inherit the problem.

How to Send an ASN: AS2, WebEDI, EDI Providers, and 3PLs

The method you use to send the 856 affects how fast and how accurately it reaches the retailer.

AS2 connection: the standard for high-volume suppliers. The ASN is generated from your ERP or WMS and sent directly over an encrypted connection, with mapping and testing completed before production.

Retailer web portals: tools like Walmart WebEDI let smaller suppliers key ASNs manually at no cost. They work for low volume but do not scale, and Walmart's WebEDI does not support DSDC shipments.

EDI provider or VAN: a third-party provider maps your shipment data to each retailer's ASN specification and handles transmission.

Third-party logistics (3PL): some suppliers let their 3PL send ASNs on their behalf. The supplier remains fully accountable for compliance, so ASN accuracy still needs to be monitored.

ASN Requirements at Walmart, Target, Amazon, and Kroger

Modern distribution centers are built around the ASN. Many large retailers rely on it for cross-docking, where goods move straight from inbound to outbound without being stored, which only works when contents are known in advance.

The efficiency gains are significant. Receiving costs are estimated to drop by about 40% when receivers can scan shipping labels instead of breaking down cartons to identify contents.

That dependence is why retailers enforce ASN rules strictly:

Walmart: the ASN must be accepted before the shipment gates in at the DC, with performance tracked in Retail Link's ASN Dashboard and SQEP Dashboard. ASN failures fall under SQEP's "Right Invoice" category, the second-largest source of SQEP fines after packaging defects.

Target: EDI 856 Availability deductions apply when a timely, error-free ASN is not received before the trailer arrives in the yard.

Amazon: freight is received through License Plate Receive, where a single scan of the carton's Parcel Identifier confirms contents against the ASN without opening the box. When that check passes, cartons move through efficient auto-receive. When it fails, cartons drop into manual, prep, or problem receiving, and miscounts there generate shortage claims even when the shipment arrived complete. Amazon's ASN chargebacks range from 1% to 6% of product cost depending on the violation and the vendor's compliance rate.

Kroger: SSCC-18 label mismatches and missing FSMA 204 Key Data Elements on food items trigger receiving problems and deductions.

How to Check ASN Status: 997, 824, and Retailer Dashboards

Sending an ASN is only half the job. Suppliers need to confirm the retailer received and accepted it.

Check the 997 acknowledgment: an accepted 997 confirms the document was received. A rejected one means the ASN never entered the retailer's system.

Monitor 824 application advice: errors require correction and retransmission before the truck arrives. Warnings do not block processing but should be fixed before a retailer converts them to errors.

Review retailer dashboards: use the retailer's ASN performance reports, such as Walmart's ASN Dashboard or Target's Supplier Performance Management Dashboard, to catch late or missing ASNs weekly.

Reconcile against receipts: compare what your ASN declared with what the retailer recorded as received. Gaps here predict the deductions that will appear on the next remittance.

Common ASN Errors That Cause Chargebacks and Shortage Claims

ASN problems rarely stay contained. A mismatch between the ASN and the physical pallet is treated as a compliance failure even when every unit is present.

The most common failures:

• Late ASN: sent after the trailer arrives, so the retailer receives it manually and fines the delay
  
• Missing ASN: never sent, or rejected on the 997 and never corrected
  
• Quantity mismatch: the ASN declares units that differ from what physically shipped, often because the ASN was built from the PO instead of pick data
  
• SSCC mismatch: when the carton label does not match the MAN segment, scan-based receiving breaks down
  
• Broken hierarchy: items not nested under the correct pack, or a pack not linked to its order
  
• Wrong time zone: ASN timestamps must reflect the DC's local time zone, or an on-time ASN can be recorded as late
  
• Unresolved warnings: 824 warnings do not block processing today, but retailers can convert them to errors in future updates

Each one pushes freight into manual receiving, where miscounts produce shortage claims, and triggers compliance charges on top: Walmart SQEP Right Invoice defects, Target ASN Availability fines, Amazon ASN accuracy chargebacks, and Kroger EDI non-compliance deductions.

Walmart applies ASN penalties at the purchase order header level under three defect types: ASN Not Downloaded, ASN Late, and ASN Inaccurate. Because they accumulate per PO, a recurring mapping error can generate weeks of fines before anyone investigates.

ASN Best Practices to Prevent Compliance Fines

• Generate ASNs from real shipment data: build the 856 from WMS pick-and-pack scans, not from PO quantities
  
• Send the ASN when the trailer leaves: best practice is to send it right after shipping labels print, before carrier pickup
  
• Validate SSCC labels at pack time: confirm every label scans and matches the ASN before freight leaves the dock
  
• Follow each retailer's mapping guide: hierarchy, required segments, and label formats differ by retailer
  
• Watch acknowledgments daily: a rejected 997 caught in the morning can be fixed before the truck arrives; one caught next week becomes a deduction

For a broader look at how ASN errors fit alongside labeling, packaging, and delivery problems, see our guide to avoiding common shipping errors.

Recover ASN-Related Deductions With iNymbus

Even suppliers with strong EDI processes see ASN-related deductions: a late transmission, a rejected acknowledgment, or a receiving miscount that the retailer blames on the ASN. Many of those charges are disputable, but only with the right 856 records, 997 timestamps, and delivery documents pulled together inside the dispute window.

iNymbus automates that recovery. It pulls ASN, shortage, and compliance deductions from retailer portals, matches each one to your EDI transmission records, acknowledgments, BOLs, and PODs, and files disputes through the correct channel before the deadline, across Walmart, Amazon, Target, Kroger, and 51+ retailers.

Talk to the iNymbus team.