Definition
An Advance Ship Notice (ASN) is an electronic message a supplier sends to a buyer, warehouse, or 3PL before a shipment arrives, describing exactly what was shipped and how it is packed. It is transmitted as the EDI 856 transaction set and covers the shipment's contents down to the order, pallet, and carton level, so the receiving dock knows what is coming before the truck shows up.
Why it matters
Receiving without an ASN means opening cartons to find out what is inside. With one, the warehouse can plan labor, pre-assign putaway locations, and check in freight by scanning carton labels against the ASN instead of counting by hand. Many large retailers require ASNs from their vendors and issue chargebacks when the ASN is late, missing, or does not match what physically arrived, which makes ASN accuracy a direct cost issue for the supplier and the 3PL handling their freight.
What an EDI 856 actually contains
The 856 is hierarchical: a shipment level (carrier, ship date, expected arrival, bill of lading or PRO number), an order level (the purchase orders covered), a pack level (pallets and cartons, usually identified by SSCC-18 serial numbers matching the barcode labels on the freight), and an item level (SKUs and quantities inside each carton). That structure is what lets a receiving system match a scanned pallet label to the exact POs and items it carries.
ASN versus arrival notice
The two are often confused and belong to different worlds. An ASN travels from a supplier to the party receiving the goods, before domestic shipment, and describes packing detail for receiving and putaway. An arrival notice travels from an ocean carrier or its agent to the consignee when a vessel is about to arrive, and starts the pickup clock at the port. A 3PL doing retail distribution lives on ASNs; an ocean import forwarder lives on arrival notices.
Where ASN work eats 3PL ops time
On the inbound side, a 3PL receiving for its customers depends on suppliers sending ASNs that are complete and on time; when they do not, the dock reverts to blind receiving and manual keying. On the outbound side, a 3PL shipping to retailers must generate accurate ASNs at pack time, since a mismatch between the 856 and the physical shipment is what triggers compliance chargebacks. In both directions the failure mode is the same: someone re-typing shipment data that already exists in a document or an email.
A delivery order or shipping document arrives by email and someone keys the entry by hand. TIO's order entry agent reads it and creates the shipping entry in the system a 3PL already runs, for a person to approve.
Learn more →Frequently asked questions
What is the difference between an ASN and a bill of lading?
A bill of lading is the contract of carriage between the shipper and the carrier and describes the freight at the shipment level for transport and liability purposes. An ASN (EDI 856) is a receiving document sent to the buyer or its warehouse describing how the goods are packed, down to pallet and carton detail, so the destination can plan and verify receipt. A shipment normally has both: the BOL for the carrier, the ASN for the receiver.
Is an ASN required?
No law requires it, but most major retailers make ASNs a condition of their vendor routing guides and back the requirement with compliance chargebacks for late, missing, or inaccurate ASNs. For suppliers shipping through a 3PL, the 3PL usually generates the ASN at pack time on the supplier's behalf, which makes ASN accuracy part of the 3PL's service obligation.
What does EDI 856 mean?
856 is the number of the ANSI X12 transaction set used to transmit an Advance Ship Notice between trading partners, so "the 856" and "the ASN" refer to the same message. Related sets in the same flow are the 850 purchase order, the 855 PO acknowledgment, and the 810 invoice.