Advance Shipment Notice (ASN) Guide

An Advance Shipment Notice (commonly abbreviated ASN) is a structured electronic notification that a shipper, supplier or carrier provides to a consignee before goods physically arrive. At its core an ASN communicates the who, what, when and how of an incoming shipment so warehouses, distribution centers, retailers and logistics partners can prepare receiving resources, schedule appointments, and automate inbound processes. ASNs are fundamental to modern supply chains because they convert blind receipts—uncertain shipments—into predictable, actionable events.

Why ASNs matter

An ASN reduces receiving time and error rates by providing item-level detail in advance. Instead of opening cartons and counting to discover what arrived, receivers can compare the ASN to purchase orders (POs), allocate dock doors and labor, pre-generate putaway tasks, and trigger exceptions before the truck arrives. The result is faster unloads, more accurate inventory records, fewer chargebacks, and improved cross-dock or same-day fulfillment capabilities.

Common ASN formats and standards

ASNs can be transmitted using several formats depending on partner capabilities and industry standards. Common formats include:

• EDI 856 — The most widely used electronic data interchange transaction for ASNs in retail and manufacturing. Defines hierarchical shipment, order and item detail segments.
• GS1 XML — XML-based ASN supporting GS1 identifiers like GTIN and SSCC and widely used where barcode/label standards matter.
• Proprietary APIs / JSON — Modern integrations use REST APIs and JSON payloads for ASNs, enabling real-time notifications and simpler parsing.
• Web portals or CSV — Smaller suppliers often transmit ASNs through a trading partner portal or flat file uploads.

Key data elements in an ASN

A useful ASN contains predictable fields that map to warehouse processes. Typical elements include:

• Shipment identifier (shipment ID, ASN number)
• Carrier and transport details (carrier name, SCAC, tracking number)
• Estimated arrival (date/time window, appointment slot)
• Purchase order references (PO numbers that the shipment covers)
• Packaging hierarchy (pallets > cartons > inner packs) with counts for each level
• Item lines (SKU, GTIN, quantity shipped, quantity per carton, unit of measure)
• Serial and batch data (lot numbers, expiry dates if required)
• SSCC / logistics label (Serial Shipping Container Code to link physical pallet labels to data)
• Hazmat or temperature requirements where applicable

How ASNs fit into inbound workflows

An ASN typically triggers a sequence of automated and human tasks in the receiving warehouse:

1. Validate ASN against expected POs in the warehouse management system (WMS) or ERP.
2. Reserve dock doors and create receiving appointments if the ASN contains arrival windows.
3. Pre-generate receiving tasks and barcoded labels tied to ASN package identifiers (SSCCs).
4. Route the shipment on arrival—cross-dock, direct putaway, quarantine for QA, or staging for returns.
5. Reconcile actual received quantities against the ASN and PO, and create discrepancy tickets if mismatches occur.

Integration patterns: EDI vs API vs Manual

Large trading partners often exchange ASNs via EDI (856) integrated into ERP or WMS software. EDI provides a standardized, batch-oriented exchange suitable for high-volume trading relationships. APIs and JSON are increasingly common for near-real-time ASNs, especially with carriers and 3PLs. For smaller suppliers, web-portal entry or flat-file uploads remain common but introduce manual steps and delay.

Sample ASN usage example (real-world)

A consumer goods supplier ships a palletized order to a retailer. They send an EDI 856 containing the shipment ASN: shipment ID, carrier SCAC, expected delivery window, PO numbers, SSCC labels for each pallet, and SKU-level counts. The retailer’s WMS receives the ASN, allocates a dock appointment, prints SSCC scanning labels for the dock, and pre-generates putaway queues. On arrival, dock personnel scan the SSCC barcodes; the WMS matches scanned pallets to the ASN and updates inventory without manual data entry—reducing receiving time and eliminating counting errors.

Best practices for ASNs

• Include SSCCs for every logistic unit to enable barcode scanning and automated reconciliation.
• Ensure consistent identifiers (GTIN, SKU) between supplier, carrier and receiver to avoid mapping issues.
• Transmit ASNs as soon as shipment is booked and update if any changes occur (quantities, ETA).
• Standardize time windows and timezone conventions to avoid appointment confusion.
• Validate ASNs against POs early and communicate exceptions immediately to avoid dock delays.
• Use versioning or amendment messages for corrected ASNs rather than re-sending entire files.

Common mistakes and pitfalls

New adopters frequently make some predictable errors:

• Sending incomplete ASNs that lack SSCCs, leading to manual handling and slower processing.
• Mismatched identifiers—supplier SKU codes that don’t map to receiver SKUs—causing reconciliation failures.
• Late ASNs that arrive after the truck, negating the benefits of pre-receiving.
• Not communicating ASN changes (amendments), so receivers plan on outdated information.
• Assuming ASN equals delivery confirmation—an ASN is predictive and must be reconciled with physical receipt.

Compliance, validation and SLAs

Many retailers and 3PLs require ASNs to meet specific data quality rules (required fields, valid GTINs, SSCC presence). Service-level agreements (SLAs) may dictate when an ASN must be transmitted relative to shipment departure or arrival. Implementing automated validation routines in middleware or the WMS helps enforce partner requirements and reduces chargebacks.

Getting started: implementation checklist

• Agree on format and transport (EDI, API, SFTP, portal).
• Map data fields (SKU/GTIN, PO, SSCC) between partners and test with sample files.
• Establish validation rules and exception handling procedures.
• Run test shipments end-to-end from ASN to physical receive and reconciliation.
• Document change control for ASN amendments and error correction workflows.

Bottom line

An effective ASN program transforms inbound logistics from reactive to proactive. When suppliers, carriers and warehouses adopt consistent ASN practices—complete with SSCC labeling, clear identifiers, and timely transmission—organizations realize measurable improvements in dock throughput, inventory accuracy and labor efficiency. For beginners, focus first on agreeing data fields and transmission method with trading partners, then iterate with validation rules and automation to scale benefits.