EDI 856: Advance Ship Notice (ASN) – Definition, Format & Examples

EDI 856 is the Advance Ship Notice (ASN) transaction set—an electronic document that tells your trading partner exactly what’s being shipped, how it’s packed, and when to expect it. The ASN arrives before the physical shipment, enabling receivers to prepare for efficient unloading, reduce check-in time, and maintain accurate inventory.

This guide covers the EDI 856 definition, format, segment specifications, and real-world examples.

EDI 856 at a Glance

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What is EDI 856 (Advance Ship Notice)?

The EDI 856, commonly called the Advance Ship Notice or ASN, is an electronic packing slip that provides detailed information about a shipment before it arrives. It answers the receiver’s key questions:

• What’s coming? – Items, quantities, lot numbers, serial numbers
• How is it packed? – Cartons, pallets, containers with hierarchy
• When will it arrive? – Carrier, tracking, estimated delivery
• What order does it fulfill? – Purchase order references

Unlike a simple shipping notification email, the EDI 856 is machine-readable—the receiver’s warehouse management system can automatically prepare receiving documents, allocate dock doors, and pre-stage inventory locations.

Why is the ASN Important?

Major retailers like Walmart, Target, and Amazon require EDI 856 compliance. Without an accurate ASN:

• Shipments may be rejected or delayed at the dock
• Chargebacks apply for missing or late ASNs
• Receiving takes longer (manual counting vs. scan-and-verify)
• Inventory accuracy suffers

EDI 856 Specification: Key Segments

The EDI 856 uses a hierarchical structure (HL loops) to represent the physical packing of a shipment. Here are the key segments:

Understanding the HL (Hierarchical Level) Structure

The HL segment is what makes EDI 856 unique—it represents how items are physically packed. Common hierarchy:

HL*1**S                    (Shipment level)
  └─ HL*2*1*O              (Order level - PO reference)
       └─ HL*3*2*P         (Pack level - pallet/carton)
            └─ HL*4*3*I    (Item level - product detail)

HL Codes:

• S = Shipment
• O = Order
• P = Pack (tare/pallet/carton)
• I = Item

EDI 856 Example

Here’s a simplified EDI 856 Advance Ship Notice example:

ISA*00*          *00*          *ZZ*SUPPLIER       *ZZ*RETAILER       *260128*1400*U*00401*000000001*0*P*>~
GS*SH*SUPPLIER*RETAILER*20260128*1400*1*X*004010~
ST*856*0001~
BSN*00*ASN123456*20260128*1400*0001~
DTM*011*20260128~
DTM*017*20260130~
HL*1**S~
TD1*CTN*10****G*250*LB~
TD5**2*UPSN*M*UPS Ground~
TD3**TL*TRAILER123~
REF*BM*BOL-2026-001~
REF*CN*1Z999AA10123456784~
N1*SF*Acme Distribution*92*ACME001~
N3*100 Warehouse Way~
N4*Chicago*IL*60601*US~
N1*ST*Retailer DC East*92*RET-DC-01~
N3*500 Receiving Blvd~
N4*Newark*NJ*07101*US~
HL*2*1*O~
PRF*PO-2026-5001~
HL*3*2*P~
MAN*GM*00100123456789012345~
TD1*CTN*5****G*125*LB~
HL*4*3*I~
LIN**UP*012345678901*VP*WIDGET-100~
SN1**100*EA~
HL*5*3*I~
LIN**UP*012345678902*VP*WIDGET-200~
SN1**50*EA~
HL*6*2*P~
MAN*GM*00100123456789012346~
TD1*CTN*5****G*125*LB~
HL*7*6*I~
LIN**UP*012345678901*VP*WIDGET-100~
SN1**100*EA~
SE*32*0001~
GE*1*1~
IEA*1*000000001~

Example Breakdown

This EDI 856 example communicates:

• Shipment: 10 cartons, 250 lbs total, shipping UPS Ground
• Trailer: TRAILER123
• BOL: BOL-2026-001
• Tracking: 1Z999AA10123456784
• From: Acme Distribution, Chicago IL
• To: Retailer DC East, Newark NJ
• Order: PO-2026-5001
• Pallet 1 (SSCC: 00100123456789012345): 5 cartons containing 100x WIDGET-100 + 50x WIDGET-200
• Pallet 2 (SSCC: 00100123456789012346): 5 cartons containing 100x WIDGET-100

How EDI 856 Works: The ASN Process Flow

1. Order Received – Supplier receives EDI 850 Purchase Order
2. Order Picked & Packed – Warehouse picks items, creates packing structure
3. Labels Generated – SSCC-18 labels applied to cartons/pallets
4. ASN Created – WMS generates EDI 856 with pack hierarchy
5. ASN Transmitted – Sent via AS2, SFTP, or VAN when shipment departs
6. 997 Acknowledgment – Receiver confirms ASN receipt
7. Shipment Arrives – Receiver scans SSCC labels to verify against ASN
8. Receiving Complete – Inventory updated automatically

Benefits of EDI 856 (Advance Ship Notice)

For Suppliers

• Faster payment – Accurate ASNs speed up receiving and invoice matching
• Fewer chargebacks – Compliance with retailer requirements
• Reduced disputes – Electronic proof of what was shipped
• Better relationships – Trading partners value reliable ASNs

For Receivers

• Faster receiving – Scan-and-verify vs. manual counting
• Dock scheduling – Know what’s coming and when
• Inventory accuracy – Automatic updates from ASN data
• Cross-docking – Route items to outbound without put-away
• Labor planning – Staff appropriately for incoming volume

Common EDI 856 Challenges

ASN Accuracy Issues

The ASN must match exactly what’s on the truck. Common errors:

• Wrong quantities (shipped vs. ASN mismatch)
• Missing items not reflected in ASN
• Incorrect SSCC-18 labels
• Wrong PO references

Timing Problems

The ASN must arrive before the shipment. If it’s late:

• Receiver can’t pre-stage
• Chargebacks may apply
• Manual receiving required

Pack Hierarchy Complexity

The HL structure must accurately represent physical packing. Mixed pallets and partial cases increase complexity.

EDI 856 Compliance Requirements

Major retailers have specific ASN requirements:

Non-compliance typically results in chargebacks ranging from $5-$50 per ASN or percentage-based penalties.

Related EDI Transactions

Implementing EDI 856

Requirements

• EDI-capable system or integration platform
• WMS that generates pack hierarchy data
• SSCC-18 labeling capability
• Trading partner implementation guides

Best Practices

• Send on ship – Trigger ASN when carrier scans pickup
• Automate from WMS – Don’t manually create ASNs
• Validate before sending – Check quantities match pick/pack
• Test thoroughly – Each retailer has unique requirements

How Comparatio Simplifies EDI 856

Comparatio’s integration platform handles EDI 856 complexity:

• Pre-built retailer maps – Walmart, Amazon, Target requirements built-in
• WMS integration – Automatic ASN generation from your warehouse system
• SSCC-18 generation – Create compliant carton labels
• Validation – Catch errors before transmission
• Real-time tracking – Monitor ASN status and acknowledgments

See how Comparatio streamlines EDI 856 compliance →

EDI 856 Data Quality and Validation

Poor data quality in EDI 856 transactions creates downstream problems that can disrupt entire supply chains. Understanding validation requirements and implementing quality controls ensures your advance ship notices meet trading partner specifications and automate receiving processes effectively.

Critical Data Elements That Must Be Accurate

Several data elements in the EDI 856 require precise validation to prevent shipment delays or chargebacks:

• UPC/GTIN codes: Must match buyer’s item master exactly, including check digits
• Purchase order references: PO numbers, line numbers, and release numbers must be valid and open
• Quantity precision: Shipped quantities cannot exceed ordered quantities unless approved
• Pack hierarchy consistency: Item quantities must roll up correctly through carton and pallet levels
• SSCC-18 barcodes: Serial shipping container codes must follow GS1 standards and be unique

Common Validation Rules by Retailer

Major retailers enforce specific validation rules for ASN acceptance:

• Walmart: Requires PRO numbers for LTL shipments, specific carrier SCAC codes, and dimensional data for certain product categories
• Target: Mandates advance notice timing (24-48 hours before delivery) and restricts partial shipment notifications
• Amazon Vendor Central: Enforces strict ASIN matching and requires carton content details for direct fulfillment

Implementing automated validation checks before EDI 856 transmission prevents costly rejections and maintains strong trading partner relationships.

EDI 856 Integration with Warehouse Management Systems

Effective EDI 856 integration transforms your warehouse operations by automating receiving processes and improving inventory accuracy. Modern WMS platforms use advance ship notice data to optimize dock scheduling, labor allocation, and put-away strategies.

Pre-Receipt Processing

When a warehouse management system receives an EDI 856, several automated processes begin before the shipment arrives:

• Dock door assignment: System allocates specific doors based on shipment size, product type, and delivery timing
• Labor planning: Receiving team schedules are adjusted based on expected workload and product handling requirements
• Put-away preparation: Inventory locations are pre-allocated for incoming items based on storage rules and available space
• Cross-dock identification: Items destined for immediate outbound shipment are flagged for expedited processing

Receipt Verification Process

The ASN enables scan-and-verify receiving instead of manual counting, dramatically reducing processing time:

• Carton scanning: SSCC-18 barcodes confirm expected contents without opening packages
• Exception handling: Discrepancies between ASN data and physical shipment trigger immediate notifications
• Quality control routing: Items requiring inspection are automatically routed to QC areas based on ASN attributes
• Real-time updates: Inventory levels update automatically as items are received and put away

This integration typically reduces receiving time by 30-50% while improving inventory accuracy to 99.5% or higher for participating suppliers.

EDI 856 Performance Metrics and Monitoring

Tracking key performance indicators for your EDI 856 processes helps identify improvement opportunities and maintains compliance with trading partner requirements. Establishing baseline metrics and monitoring trends prevents service disruptions.

Essential ASN Metrics

Monitor these critical metrics to ensure optimal advance ship notice performance:

• Transmission success rate: Percentage of EDI 856 transactions transmitted without technical errors (target: 99.5%)
• Data accuracy rate: Percentage of ASNs with no data discrepancies upon receipt verification (target: 98%)
• Timing compliance: Percentage of ASNs sent within required time windows before delivery (target: 100%)
• Acknowledgment response time: Average time to receive 997 functional acknowledgments from trading partners

Performance Optimization Strategies

Use performance data to drive continuous improvement in your ASN processes:

• Error pattern analysis: Identify recurring data quality issues and implement preventive controls
• Trading partner scorecards: Track performance by customer to prioritize improvement efforts
• Seasonal planning: Adjust transmission schedules and validation rules during peak shipping periods
• Exception reporting: Create automated alerts for failed transmissions or compliance violations

Companies tracking these metrics typically achieve 15-20% improvement in ASN accuracy within six months while reducing trading partner chargebacks by 40-60%.

Summary

EDI 856 (Advance Ship Notice) is essential for modern supply chain efficiency. It enables receivers to prepare for incoming shipments, speeds up dock-to-stock time, and maintains inventory accuracy through scan-based verification.

Key points:

• EDI 856 is the electronic packing slip sent before shipment arrives
• The HL segment creates a hierarchy matching physical pack structure
• SSCC-18 labels enable scan-and-verify receiving
• Major retailers require ASN compliance with specific timing and format rules
• Accurate ASNs reduce chargebacks and speed up payment

Frequently Asked Questions

What is EDI 856?

EDI 856 is the Advance Ship Notice (ASN) transaction set in the ANSI X12 standard. It electronically communicates shipment details—what’s being shipped, how it’s packed, and when it will arrive—before the physical delivery.

What is an Advance Ship Notice (ASN)?

An Advance Ship Notice is an electronic packing slip sent before a shipment arrives. It tells the receiver exactly what to expect: items, quantities, packaging, carrier, tracking, and estimated delivery. EDI 856 is the standard format for ASNs.

When should EDI 856 be sent?

The ASN should be transmitted when the shipment leaves the origin—typically when the carrier scans the pickup. Some retailers require ASNs within 30 minutes of ship confirmation. Sending early (before ship) or late (after delivery) can result in chargebacks.

What is SSCC-18?

SSCC-18 (Serial Shipping Container Code) is an 18-digit identifier for logistics units (cartons, pallets). It’s encoded in GS1-128 barcodes on shipping labels and referenced in the EDI 856 MAN segment. SSCC-18 enables scan-based receiving.

What’s the difference between EDI 856 and EDI 810?

EDI 856 (ASN) describes what’s being shipped. EDI 810 (Invoice) requests payment for what was shipped. The 856 is sent at ship time; the 810 is sent after delivery or per payment terms. Many receivers match the 810 against the 856 for three-way matching.

Do all retailers require EDI 856?

Most major retailers require EDI 856 for direct shipments to distribution centers. Requirements vary—some need carton-level detail, others accept pallet-level. Always check your trading partner’s implementation guide for specific requirements.