What Is an ASN in Shipping?
An ASN, or Advance Ship Notice, is an electronic document a supplier sends to a buyer before a shipment arrives. In EDI terms, the ASN is the X12 856 transaction set. It lists what is in the shipment, how it is packed, the carrier and tracking number, the ship date, and the expected delivery date - giving the receiving warehouse everything it needs to pre-stage labor, dock doors, and put-away locations before the truck shows up.
ASN Meaning in Shipping vs. EDI 856
"ASN" and "EDI 856" describe the same business document. "ASN" (or "advance shipping notice") is the supply-chain term retailers and 3PLs use. "EDI 856" is the technical X12 transaction set that encodes the ASN so it can be transmitted between trading partners. If a retailer asks for an ASN, they are asking for an 856.
What Is an ASN in EDI? Hierarchical (HL) Structure
The 856 uses a hierarchical loop (HL) structure that describes a shipment from the top down. The most common pattern is SOPI - Shipment, Order, Pack, Item:
- Shipment (S) - carrier SCAC, BOL number, tracking, ship date, estimated delivery, weight, and ship-from/ship-to locations.
- Order (O) - purchase order number and order-level details, linking the shipment back to the 850.
- Tare (T) - pallet or container packaging, including SSCC-18 license-plate numbers.
- Pack (P) - case or carton details with GS1-128 carton IDs and quantities.
- Item (I) - individual SKUs with UPC/GTIN, lot, serial, and quantity shipped.
Why the Advance Shipping Notice Matters
Accurate ASNs are how modern warehouses run cross-docking, automated receiving, and scan-and-pack put-away. They also drive three-way matching: the 850 (PO), the 856 (ASN), and the 810 (Invoice) must agree for invoices to auto-pay. A late or inaccurate ASN slows receiving, delays payment, and triggers chargebacks.
- Walmart charges roughly $2-$3 per case for late or missing ASNs under its OTIF program.
- Target requires the 856 to be transmitted before the carrier picks up the shipment.
- Amazon deducts Vendor Scorecard points for ASN inaccuracies and missed cutoffs.
- Kroger, Costco, and Home Depot all assess fines for ASN/label mismatches.
GS1-128 Labels and the ASN
Every carton and pallet on the shipment must carry a GS1-128 (formerly UCC-128) label whose SSCC-18 serial number matches the ASN exactly. When the receiver scans a carton, the SSCC tells their WMS which 856 record to look up - and from there, exactly what is inside. If a single SSCC on the truck does not match the 856, the entire shipment can be rejected.
ASN Timing Requirements
Most large retailers require the 856 to be transmitted within a tight window around the physical shipment - typically before the truck leaves the dock, and no later than one hour after departure. Missing the window is treated the same as a missing ASN.
Common ASN / EDI 856 Errors
These are the issues that drive the majority of ASN chargebacks Yoke sees in production:
- Carton counts on the 856 do not match the physical pallet.
- SSCC-18 numbers are reused across shipments or are missing leading zeros.
- UPC/GTIN values do not match the buyer's item master.
- ASN is transmitted after the goods are already received.
- Ship-to location code does not match the PO's destination.
How Yoke Handles EDI 856 for You
Yoke maps your ERP, WMS, or 3PL data into a compliant 856 for every trading partner, generates GS1-128 labels that match the ASN byte-for-byte, monitors timing windows, and validates each 856 against the originating 850 before transmission. If a partner changes their 856 spec, we update the map - you do not.
Frequently Asked Questions
Quick answers to the questions buyers and suppliers ask most about this transaction.
- What is an ASN in shipping? An ASN (Advance Ship Notice) is an electronic document sent by a supplier to a buyer before a shipment arrives, listing what was shipped, how it is packed, the carrier, and the expected delivery. In EDI, the ASN is the X12 856 transaction set.
- What is the difference between an ASN and an EDI 856? There is no business difference. "ASN" is the supply-chain term and "EDI 856" is the technical X12 transaction set that carries the ASN between trading partners.
- When does the EDI 856 need to be sent? Most major retailers require the 856 to be transmitted before the carrier picks up the shipment, or within a short window (often one hour) after the truck departs. Late ASNs are treated as missing ASNs for chargeback purposes.
- How does the ASN relate to GS1-128 labels? Each carton or pallet carries a GS1-128 label with an SSCC-18 serial number that must match the SSCC in the 856 exactly. The receiver scans the SSCC to pull the matching ASN record and validate contents.
- What happens if an ASN is wrong? Inaccurate ASNs cause receiving delays, failed three-way matching, payment holds, and per-carton chargebacks. Walmart, Target, Amazon, and Kroger all assess penalties for ASN errors.