EDI 945 vs EDI 856 (ASN): Key Differences

The ANSI X12 warehouse shipping advice transaction sent by a warehouse or 3PL after shipment.

EDI 945 The ANSI X12 warehouse shipping advice transaction sent by a warehouse or 3PL after shipment. Comparing it to the EDI 856 (ASN) helps logistics teams choose the right messages and align expectations between suppliers, warehouses, carriers, and receivers.

Both the 856 and 945 communicate outbound shipment information, but they serve different purposes and are used at different points in the shipping lifecycle. Understanding their distinctions prevents duplicate efforts, reduces reconciliation errors, and clarifies which message is authoritative for inventory and billing.

Primary Purpose And Timing

The EDI 856 (ASN) is an advance notice. It is sent prior to or during shipment to inform the receiver what to expect — contents, packing structure, and planned arrival. It helps receivers prepare docks, schedule labor, and pre-allocate shelf or staging space.

The EDI 945 is a confirmation sent after the goods have been shipped. It records what physically left the warehouse, making it the authoritative record for invoicing, inventory decrements, and carrier handoff documentation.

Who Typically Sends Each Message

• EDI 856 Sender: Usually the shipper or supplier who wants to advise the buyer in advance — manufacturers, distributors, or retail suppliers.
• EDI 945 Sender: The warehouse operator or 3PL that actually completed the shipment and can confirm final counts and carrier details.

Content Differences

An ASN often includes planned packing hierarchies (pallets, cartons), estimated quantities, and expected carrier/timing. It’s common to include proposed carton IDs and declared weights for planning. In contrast, a 945 focuses on confirmed counts, actual carrier identifiers (PRO number, pallet IDs scanned at tender), and any adjustments that occurred during picking or loading.

Because the 945 is post-event, it may include corrections to the original ASN: quantities reduced due to shortages, extra cartons added because of split orders, or different carrier details if a last-minute carrier change occurred.

How Systems Use Them

Receiving systems typically consume the ASN to pre-populate expected receipts and trigger receiving windows. Inventory systems may place expected inbound quantities on hold until a receiving confirmation. When the 945 arrives, it reconciles against the ASN and receiving transactions to finalize inventory and trigger invoicing and accounts-payable reconciliation.

ERP and WMS workflows should be configured to accept both messages but give precedence to the 945 for final inventory adjustments and billing, while using the ASN for planning and appointment scheduling.

Common Scenarios And Recommendations

• Scenario: ASN predicted 200 units, 945 reports 195. Action: Receiver flags five-unit shortage, holds invoice, and opens discrepancy claim.
• Scenario: No ASN sent but 945 arrives. Action: Receiver treats shipment as unannounced — creates inbound receipt and updates inventory based on the 945.
• Recommendation: Establish partner rules that define whether the ASN or 945 is the master for specific reconciliation steps to avoid double-processing.

Integration Considerations

When integrating trading partners, document which segments each party expects in the 856 and 945. Some customers require both messages; others accept the 945 alone. Agree on identifiers (PO numbers vs. release numbers), carrier references, and packaging levels to avoid mapping ambiguities.

Testing scenarios should include matched shipments, short shipments, overages, and carrier changes so both ASN and 945 mappings are validated under real operational conditions.

Practical Guidance

Use the ASN for visibility and the 945 for confirmation. Automate reconciliation so ERPs and WMSs compare ASN vs. 945 and flag exceptions immediately. Maintain clear SLAs with trading partners describing which message triggers invoicing and how corrections are handled.

In short, the EDI 945 is the after-the-fact shipping advice complementary to the EDI 856 ASN. The ASN plans and alerts; the 945 confirms and settles. Properly distinguishing and using both reduces disputes and improves fulfillment accuracy.