Advance Shipping Notice Explained: EDI 856 From the Dock

What Is an ASN in Shipping?

If you are asking what is an ASN in shipping, here is the short answer: it is a digital preview of a shipment. The notice tells the receiving facility what is coming, how it is packed, and when to expect it, so the dock can prepare before the trailer backs in.

The term advance shipping notice also appears as "advanced shipping notice" or "advance ship notice." All three name the same document. In North America, trading partners usually exchange it through EDI (electronic data interchange, the standardized computer-to-computer transfer of business documents) as the X12 856 transaction set. Elsewhere, the equivalent is typically the EDIFACT DESADV message.

Who Sends an ASN, Who Receives It, and When

The shipper originates it. That could be a manufacturer, distributor, supplier, or a 3PL shipping on a client's behalf. On the other end sits the buyer's DC, a retail store, or a 3PL taking in inbound freight.

Timing matters. The message goes out after picking and packing are finished and the shipment is confirmed. That is usually when the trailer is loaded or departs, and always before the freight arrives. Transmitting it while packing is still in progress is a frequent source of errors, because the data no longer matches what actually left the building.

What an Advance Shipping Notice Contains

A typical notice carries five layers of detail:

• Shipment: ship date, estimated delivery, ship-from and ship-to locations, total weight and carton count, bill of lading (BOL) or PRO number
• Carrier: SCAC (Standard Carrier Alpha Code), transport mode, trailer or tracking number
• Order: the purchase order number or numbers being fulfilled
• Tare and pack: pallet and carton identifiers, usually SSCCs (Serial Shipping Container Codes, the 18-digit GS1 numbers printed on GS1-128 labels)
• Item: SKU, UPC or GTIN, quantity shipped, unit of measure, and sometimes lot or expiration data

Why Retailers and DCs Require ASNs

Receivers insist on this document because it turns unknown freight into known data. With it in hand, a DC can schedule dock doors and labor, scan one pallet label instead of counting every unit, and update inventory the moment goods are received. It can also send product straight to cross-dock lanes without putting it away. Retailers gain open-to-buy and replenishment visibility before anything physically arrives. That is why many make an accurate, on-time ASN a condition of doing business and enforce it through vendor compliance programs.

ASN vs. Bill of Lading vs. Packing Slip vs. Invoice

People often confuse the ASN with other shipping and billing paperwork because all four carry overlapping data: PO numbers, quantities, ship-to addresses. What separates them is purpose, audience and timing. Only the ASN is built to arrive electronically before the truck does. That gives the receiving team time to plan labor and receive cartons by scan instead of by hand count.

Comparison Table: Four Shipping Documents

Document	Primary purpose	Sent by / to	Format and timing
ASN (EDI 856)	Detailed electronic preview of shipment contents and packing hierarchy	Shipper to receiver	X12 856, EDIFACT DESADV or API; sent after packing, before arrival
Bill of lading (BOL)	Contract of carriage and receipt for goods	Between shipper and carrier; rides with the load	Paper or electronic; issued at pickup
Packing slip	Physical contents list for checking on arrival	Supplier to consignee, inside or on the cartons	Paper; travels with freight
Invoice (EDI 810)	Request for payment	Seller to buyer	X12 810, paper or PDF; sent after shipment

Each document answers a different question. The BOL governs liability while goods are in transit, the packing slip helps a person verify what is in a box, and the invoice starts the payment process. Only the ASN can feed a warehouse system enough detail to receive the freight automatically. Some companies are testing shared ledgers to keep these records consistent across trading partners, an idea covered in our piece on how blockchain technology may benefit the supply chain.

Where the ASN Fits: 850 > 856 > 997 > 810

A typical EDI order-to-cash cycle, built on transaction sets defined by ASC X12, runs like this:

1. The buyer issues an EDI 850 purchase order.
2. The supplier may reply with an EDI 855 PO acknowledgment, which some trading partners require.
3. The supplier picks, packs and ships the order, then transmits the EDI 856.
4. The buyer's system sends back an EDI 997 functional acknowledgment. This confirms the 856 arrived and passed syntax checks; it says nothing about whether the contents are accurate.
5. The supplier sends the EDI 810 invoice.

Many buyers match the 810 against both the 850 and the 856 before approving payment. Because of that three-way check, a sloppy ship notice can hold up cash as well as receiving. The accuracy of what leaves your dock matters to finance just as much as it does to the warehouse.

How the EDI Advance Shipping Notice (EDI 856) Works

The 856 is the most structurally demanding document most suppliers send, because it must describe how goods were packed as well as what shipped. Nested levels let a receiver scan one pallet label and see every carton and unit inside. The notes below follow the X12 standard, but each retailer's implementation guide dictates the exact segments, qualifiers, and hierarchy it expects. Build to that guide first and treat any general description, including this one, as background.

The Envelope and the BSN Segment

Every 856 travels inside three nested envelopes. The ISA/IEA interchange envelope identifies sender and receiver. The GS/GE functional group bundles documents of one type, with GS01 set to SH for ship notices. The ST/SE pair wraps a single transaction, and SE reports how many segments it contains, so a miscount causes a syntax rejection.

The first business segment is BSN, the Beginning Segment for Ship Notice. It carries the purpose code (00 for an original), a unique shipment ID, the creation date and time, and a hierarchical structure code such as 0001, which signals a Shipment, Order, Packaging, Item layout.

The HL Hierarchy: Shipment > Order > Tare > Pack > Item

The HL (hierarchical level) segment builds the tree. Each HL has its own ID, a parent ID, and a level code. Every segment after it belongs to that level until the next HL appears, which is why the repeating group is often called the HL loop.

• S (Shipment): carrier, weights, BOL, origin and destination parties
• O (Order): PO number and order-level references
• T (Tare): a pallet, identified by its SSCC
• P (Pack): a carton, identified by its SSCC
• I (Item): product identifiers and quantities

One shipment can hold many orders, and each order can hold pallets, cartons and items beneath it. The parent IDs are what tell a receiving system that a given carton sits on a given pallet.

SOPI vs. SOTPI and Standard Pack vs. Pick and Pack

SOPI (Shipment, Order, Pack, Item) skips the pallet level, which is typical for parcel or floor-loaded freight. SOTPI (Shipment, Order, Tare, Pack, Item) adds Tare so palletized loads can be received with one scan of the pallet SSCC.

These structures are often discussed alongside two packing styles. Standard pack puts a single SKU in a fixed quantity per carton, and some partners model it as Shipment, Order, Item, Pack instead. Pick and pack mixes SKUs, so every carton lists its own contents. Your warehouse system should support each layout per customer, a point worth weighing when choosing the right WMS.

Key 856 Segments at a Glance

• TD1: packaging type, lading quantity and gross weight
• TD5: carrier routing, including SCAC and transport method
• REF: reference numbers, such as BM for the BOL or CN for a PRO number
• DTM: dates, such as 011 for shipped and 067 for estimated delivery
• N1: party identification, such as the shipper (SF) and the receiving location (ST)
• PRF: purchase order reference at the Order level
• MAN: marks and numbers; the GM qualifier carries an SSCC at the Tare or Pack level
• LIN: item identification such as UPC, GTIN, or buyer and vendor part numbers
• SN1: item detail, including quantity shipped and unit of measure
• CTT: transaction totals, such as the count of HL segments

Segments like BIG and IT1 belong to the 810 invoice, not the 856. Seeing them in a ship notice map usually means something was copied from the wrong template.

Annotated Sample EDI 856 Snippet

This placeholder SOTPI example covers one PO, one pallet, and one carton:

ST8560001~ BSN00SH104522024061214300001~ DTM01120240612~ HL1S~ TD1CTN2512G240LB~ TD52ABCDM~ REFBMBOL778899~ N1STDC 0452920452~ HL21O~ PRF4500012345~ HL32T~ MANGM001234567000000017~ HL43P~ MANGM001234567000000024~ HL54*I~ LINUP012345678905~ SN1**24EA~ CTT5~ SE19*0001~

How to read it:

• BSN: 00 marks an original, SH10452 is the shipment ID, followed by date, time and structure code 0001.
• DTM*011: the ship date.
• TD1: 12 cartons weighing 240 pounds gross.
• TD5: carrier SCAC ABCD, motor transport.
• N1*ST: the ship-to DC.
• HL*3 and HL*4: the pallet and the carton nested inside it, each carrying its SSCC in a MAN segment.
• SN1: 24 each shipped.
• CTT*5 and SE*19: five HL segments and nineteen segments in total, counted from ST through SE.

EDIFACT DESADV: The International Equivalent

Outside North America, trading partners often use the UN/EDIFACT DESADV (Despatch Advice) message. It does the same job with different syntax. BGM identifies the message, DTM carries dates, and NAD names the parties. CPS (consignment packing sequence) builds the packing hierarchy much as HL loops do, PAC describes packages, GIN carries SSCCs, and LIN and QTY describe items and quantities. A WMS serving global customers should map the same pack data to either format.

How ASNs Are Transmitted: VAN, AS2, Web EDI, and API

• VAN (value-added network): a third-party mailbox service that routes EDI documents between partners
• AS2: a secure internet protocol for direct, encrypted exchange with signed receipts, defined in RFC 4130
• Web EDI: browser-based portals where low-volume suppliers key or upload notices
• API: JSON or XML integrations, increasingly common with marketplaces, carriers and 3PL platforms

Whichever channel you use, a 997 confirms delivery and syntax only. Whether the content is accurate depends on what your dock actually scans.

How ASNs Power Warehouse Receiving and Shipping

An ASN only pays off when the warehouse acts on it. Inbound, it changes receiving from counting into verifying. Outbound, the floor is the one place where the true packing hierarchy is known, so the warehouse system is the natural source of an accurate 856.

Inbound: Dock Scheduling and Pre-Receiving

As soon as an inbound ASN lands, the WMS can create an expected receipt ahead of the truck. Supervisors see pallet and carton counts, weights, and estimated arrival. They can then assign doors, plan labor, and flag priority or cross-dock freight. With SSCCs preloaded, receivers know which labels should come off the trailer.

ASN-Based Receiving vs. Blind Receiving

Blind receiving means staff count and identify everything with no reference data, then reconcile against the PO afterward. Done carefully it is accurate, but it is slow and labor-heavy.

ASN-based receiving replaces most of that counting with scans. A typical flow:

1. Scan the trailer or ASN reference at the door.
2. Scan each pallet's GS1-128 label. The system matches the SSCC and receives every carton and item on it in one step.
3. Scan loose cartons individually.
4. Audit-count a sample, or every pallet from suppliers whose notices are often wrong.
5. Close the receipt and post inventory.

Most DCs keep blind receiving as a fallback for missing or invalid notices.

Putaway, Cross-Docking, and Discrepancy Handling

Because SKU, quantity, and lot are known for each pallet, directed putaway can assign a location immediately. Goods already allocated to outbound orders can bypass storage and go straight to shipping lanes.

When the freight differs from the notice, capture the difference at scan time:

• Overages: unexpected SSCCs or extra units.
• Shortages: expected SSCCs that were never scanned.
• Damages: items received but quarantined.

Those exceptions feed supplier performance tracking, claims, and retail vendor compliance reporting. If you are comparing systems on this point, these tips for choosing WMS software cover what to look for.

Outbound: Building the 856 From Pick/Pack/Scan Data

Suppliers and 3PLs can assemble the ship notice from events the WMS already records:

1. Pick confirmation logs SKUs, lots, and quantities per order.
2. Pack confirmation assigns items to a carton and prints its SSCC label.
3. Palletizing scans cartons onto a pallet with its own SSCC, forming the Tare level.
4. Load confirmation captures carrier, SCAC, BOL, and trailer.
5. Ship confirmation builds the SOPI or SOTPI hierarchy per customer and transmits the 856.

Every level comes from a scan, so the document reflects what physically shipped, not what was planned.

ASN Compliance and Common Errors

Retailers and large distribution centers plan labor, dock doors and putaway around inbound ASN data, so most of them write strict rules into vendor compliance manuals. Those rules differ from one trading partner to the next, and each guide lists its own penalties. Treat your customers' documentation as the source of truth instead of relying on any industry-wide figure.

Timing Windows and Accuracy Requirements

Most partners expect the notice within a set window. That window is usually measured from shipment departure, and the notice must always reach the receiver ahead of the load. On short transit lanes, freight can reach the dock within hours, which leaves little room for a batch job that runs once a day. Accuracy rules generally cover PO numbers, item identifiers, quantities, carton counts, SSCCs and carrier details. Every value must agree with what is physically on the trailer and with the original 850.

Label-to-ASN Mismatches and Chargeback Risk

The costliest error is a GS1-128 label carrying an SSCC that never made it into the transmission. A close second is a carton listed with contents that differ from what is inside the box. When the receiver's scan finds no match, that freight falls back to manual receiving: counting, keying and staging pallets in aisles while someone sorts out the discrepancy. Extra handling and cluttered docks also raise the hazards covered in our guide to warehouse safety. Retailers commonly charge back vendors for late, missing or inaccurate ASNs and for noncompliant labels. Repeated problems can also drag down vendor scorecards and delay payment when the 810 invoice cannot be reconciled against receipts.

Checklist: Frequent EDI Advance Shipping Notice Mistakes and How a WMS Prevents Them

• Late transmission: the WMS sends the 856 automatically at ship confirmation.
• Sent before packing is final: generation stays locked until the load is confirmed.
• Quantity errors: SN1 values come from scanned picks, not ordered quantities.
• Label and data mismatch: labels and the EDI file draw on one SSCC record created at pack.
• Duplicate or reused SSCCs: serials are assigned in sequence under your GS1 company prefix.
• Wrong hierarchy (SOPI vs. SOTPI): customer-specific profiles control the structure.
• Missing or wrong PO references: PRF values carry over from the imported 850.
• Incorrect carrier or BOL data: TD5 and REF (BM) segments are recorded during load confirmation.
• Unmonitored rejections: a dashboard alert fires when a 997 is missing or reports errors.

Automating ASNs with a Warehouse Management System

Every section above leads to the same conclusion: whether an ASN is accurate gets settled on the warehouse floor, long before the EDI translator sees it. A warehouse management system built around that principle captures shipment data at the moment it is created, with a scan, and can use that single record to produce outbound notices and to consume inbound ones. When fewer values are typed by hand, fewer carton counts, quantities or tracking numbers drift away from what is really on the trailer.

Outbound: Scan-Level Data Into On-Time 856s

In a scan-driven WMS, each pick, pack and pallet build can be logged as it happens. Shipping labels with SSCCs can print from those same records, and when the shipment is confirmed, the system can assemble whatever hierarchy a given partner expects, whether that is a full SOTPI tree or a SOPI layout for parcel and mixed-SKU cartons.

When labels and the 856 come from the same scanned data, the label-to-ASN mismatches and quantity errors behind many chargebacks become far less likely, because there is no second copy of the information to fall out of sync. Timing benefits as well: the transmission can fire as soon as the shipment is confirmed rather than hours later when someone finds time to key it in. Consider a hypothetical load of 40 mixed pallets headed to a big-box retailer. If a packer swaps one carton at the last minute, the rescan updates the pallet record, and the retailer gets a notice that matches the freight.

Inbound: Using ASNs to Accelerate Receiving

A WMS can turn incoming notices into expected receipts as soon as they arrive. Supervisors can see what is coming, assign doors and schedule receiving labor before the truck backs in.

At the dock, receivers scan the label on each pallet or case to receive by SSCC instead of counting every case against a paper list. Directed putaway or cross-dock routing follows right away, so freight bound for an outbound order can move straight across the building. When the physical count and the expected receipt disagree, overages, shortages and damages are logged as exceptions at the point of scan, giving the team a clear record to resolve with the vendor.

For third-party logistics providers, the same workflow can span many clients and trading partners, each with its own ASN requirements, from a single system.

Request a Demo to see Cadre Technologies' warehouse management software for yourself.

Frequently Asked Questions

What is an advance shipping notice?

An advance shipping notice is a digital preview of a shipment that tells the receiving facility what is coming, how it is packed, and when it should arrive. In North America it is usually exchanged as the X12 EDI 856 transaction set, while international partners often use the EDIFACT DESADV message. It lists shipment, carrier and order details, SSCCs for pallets and cartons, and item quantities.

When should an ASN be sent to the receiver?

An ASN should go out after picking and packing are finished and the shipment is confirmed, typically when the trailer is loaded or departs, and always before the freight arrives. Sending it while packing is still underway is a common cause of errors because the data no longer matches what actually shipped. Many retailers set a specific timing window in their vendor compliance manuals.

What is the difference between an ASN and a bill of lading?

An ASN is an electronic record of shipment contents and packing hierarchy sent from shipper to receiver before arrival, while a BOL is the contract of carriage between shipper and carrier. The BOL rides with the load and governs liability in transit. Only the ASN carries enough detail, such as SSCCs for each pallet and carton, for a warehouse system to receive freight automatically.

What is the difference between SOPI and SOTPI in an EDI 856?

Both are hierarchy structures for the 856. SOPI covers shipment, order, pack and item levels and skips the pallet, which suits parcel or floor-loaded freight. SOTPI adds a tare level so a receiver can scan one pallet SSCC label and receive every carton and item on it in a single step. Each retailer's implementation guide specifies which layout it expects from suppliers.

Does a 997 acknowledgment mean my ASN was accurate?

No. An EDI 997 functional acknowledgment only confirms that the 856 arrived and passed syntax checks; it says nothing about whether quantities, SSCCs or PO references match the freight. Accuracy depends on what your dock actually scanned. Watching for missing or error-reporting 997s still matters, because an unnoticed rejection can turn into a chargeback.

What causes ASN chargebacks from retailers?

Retailers commonly charge back vendors for late, missing or inaccurate ASNs and for noncompliant labels. The costliest error is a GS1-128 label carrying an SSCC that never made it into the transmission, which forces the receiver into manual counting and staging. Generating both the labels and the 856 from one scanned SSCC record created at pack prevents that mismatch.