An accurate ASN (the EDI 856 Advance Ship Notice) tells the receiving DC exactly what is on the truck before it arrives: which orders, which cartons and pallets, which items and quantities in each, and the label serial number that ties each physical carton to its line in the file. Retailers use it to schedule labor, receive by scanning instead of counting, and match your invoice. When the ASN is late, incomplete, or does not match the cartons, the DC receives by hand, and the supplier usually pays for it in a chargeback.
Getting ASNs right comes down to three decisions: the right pack hierarchy for how you ship, the right moment to send, and data that comes from what was packed. All three are below, with a checklist at the end. For the document structure, see our EDI 856 reference page.
What an ASN does for each side
For the receiver, the ASN means planned dock appointments and labor, scan-based receiving, faster putaway, and immediate visibility into shortages or overages.
For the supplier, the ASN creates the receiving record in the retailer's system, which speeds up invoice matching and payment. It is also a record of what you shipped if a dispute comes up, and ASN accuracy and timeliness are scored on most retailer scorecards. Our guide to retailer performance ratings covers how those scores affect the relationship.
Pack hierarchies: how the 856 is structured
An 856 is built from HL (hierarchical level) segments nested inside each other. Each HL is one of these levels:
Code | Level | What it describes |
|---|---|---|
S | Shipment | The whole load: carrier, bill of lading, ship date, ship-from, ship-to |
O | Order | Each purchase order on the shipment |
T | Tare | A pallet or other container holding cartons |
P | Pack | A carton, with its SSCC from the GS1-128 label |
I | Item | A product and quantity |
The order of those levels is the hierarchy, and retailers specify which one they want. The common ones:
Hierarchy | Structure | Use it when |
|---|---|---|
SOPI (pick and pack) | Shipment, Order, Pack, Item | Cartons hold mixed items, so each carton lists its own contents |
SOTPI (pick and pack with pallets) | Shipment, Order, Tare, Pack, Item | Mixed cartons on pallets, and the retailer wants pallet-level detail |
SOIP (standard pack) | Shipment, Order, Item, Pack | Each carton holds one item in a standard case quantity, so each item lists the cartons it shipped in |
SOTI | Shipment, Order, Tare, Item | Pallet-level detail without individual carton labels, such as full pallets of one item |
SOI | Shipment, Order, Item | The partner only wants quantities by order, with no carton detail |
Some partners also accept SOTP or other variations. The rule that matters: use the hierarchy in the partner's implementation guide, and if the guide allows more than one, choose based on how your warehouse packs. A supplier who ships mixed cartons but sends a standard pack ASN will produce a file that cannot be reconciled at the dock.
When to send the ASN
Most retailers want the ASN after the shipment is confirmed and before it arrives. Inside that window, two things go wrong.
Send too early, and the details change after the file goes out: a different trailer, a carrier swap, a carton pulled for damage. The ASN no longer matches the truck.
Send too late, and the truck beats the file. We once worked with a supplier whose 3PL sat across the street from the retailer's DC. The 3PL's 945 triggered the 856 automatically, which looked right, but the supplier kept getting chargebacks. The driver was taking the load straight across the street and arriving a few minutes before the ASN did.
So the rule is to send as soon as the shipment is confirmed, and check that the ASN can reach the partner before the shortest possible transit time. For very short lanes, that may mean triggering the 856 at load close instead of waiting for the 945. Each retailer's guide states its own window; follow it exactly. Walmart, for example, requires that the ASN pass validation before the shipment gates in.
The errors behind most ASN chargebacks
Carton contents do not match the file
This happens when the ASN is built from the order instead of from what was packed, or when labels are printed before picking is finished. Build the ASN from pack data: your WMS, your shipping system, or the 3PL's 945.
SSCC mismatches
Each carton's SSCC (the 18-digit serial number on its GS1-128 label) must appear in the ASN exactly once. Reprinted labels, duplicate serials, and labels applied to the wrong carton all break the match.
Wrong or missing references
The PO number, department, store or DC number, bill of lading, and carrier SCAC must match the order and the routing instructions. Pull them from the 850 and the 754 instead of keying them. Our SCAC code lookup and 753 routing guide cover the carrier side.
Weights and quantities that do not add up
Retailers reconcile ASN weights against the bill of lading and what the scale says at receiving. Reporting net weight where gross is expected is a common trigger. See pack vs tare vs net weight.
Missing mandatory fields
Every partner marks different fields as required, including lot numbers and expiration dates for many food and beverage partners. A validation step that checks each partner's required fields before the file goes out catches these.
No one checks the acknowledgment
After the 856 goes out, confirm it was accepted. The partner's 997 confirms the file was readable, and an 824 reports if the content was rejected. Someone has to watch both and resend quickly. Surpass customers see acknowledgment status in the Transaction Manager Portal, through the API, or as alerts.
For the cost side of these errors, see our guides to chargeback prevention, Walmart's SQEP program, and EDI compliance in food and beverage.
When a 3PL ships for you
With a 3PL, the ASN depends on data from someone else's warehouse. The 940 tells the 3PL what to ship and should carry the retailer's labeling and hierarchy requirements. The 945 comes back with cartons, SSCCs, and tracking, and your 856 is built from it. If the 3PL cannot send carton-level detail in the 945, you cannot build a pick and pack ASN, so confirm that before onboarding a retailer that requires one. Our 945 guide and 3PL integration guide go deeper.
Pre-send ASN checklist
The hierarchy matches the partner's guide and how the shipment was packed.
Every carton on the truck appears once, with the SSCC from its label.
Item quantities per carton add up to the shipped quantity per PO line.
PO, store or DC, bill of lading, and SCAC match the 850 and 754.
Weights are the type the partner asks for and match the bill of lading.
All partner-required fields are present, including lot and expiration data if required.
The ASN will arrive before the truck, given the lane's shortest transit time.
Someone is watching for the 997 and any 824.
Frequently asked questions
What is an ASN in EDI?
An ASN, or Advance Ship Notice, is the EDI 856 transaction set. It tells the receiver what is in a shipment, how it is packed, and when it will arrive, before the shipment gets there.
What are the advantages of ASNs?
Receivers can plan labor and dock space, receive by scanning instead of counting, and spot discrepancies right away. Suppliers get faster invoice matching and payment, a record of what shipped, and better scorecard results.
What is the difference between pick and pack and standard pack ASNs?
A pick and pack ASN (SOPI) lists the contents of each carton, for cartons with mixed items. A standard pack ASN (SOIP) lists each item and the cartons it shipped in, for cartons that each hold one item in a standard quantity.
When should an ASN be sent?
After the shipment is confirmed and before it arrives, inside the window the retailer's guide specifies. On short lanes, trigger the ASN at load close so the file arrives before the truck.
Why do ASNs cause chargebacks?
Retailers charge back when the ASN is late or missing, when its contents or label serial numbers do not match the cartons, or when required fields are missing, because the DC has to receive by hand.
What is an SSCC on an ASN?
The SSCC (Serial Shipping Container Code) is the 18-digit number on each carton's or pallet's GS1-128 label. The ASN lists it so the receiver can scan the label and match the carton to its contents in the file.
Is an ASN the same as a bill of lading?
No. The bill of lading is the carrier's shipping document and contract of carriage. The ASN is an EDI document sent to the receiver with carton-level detail. The ASN usually references the bill of lading number. See our bill of lading guide.
Send ASNs that match the truck
Surpass builds 856s from your pack data or your 3PL's 945, validates each partner's required fields before sending, and tracks every acknowledgment. See how we work with consumer goods and food and beverage brands, or talk to our team.
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