EDI 855 Versus EDI 860: Acknowledgment, Change Order, And When To Use Each

The ANSI X12 purchase order acknowledgment transaction.

EDI 855 The ANSI X12 purchase order acknowledgment transaction. It signals a seller’s acceptance, rejection, or change to a buyer’s original purchase order; compare that to other X12 transactions like the 860 change order which is used by buyers to modify a PO after issuance.

Logistics teams often confuse the roles of the 855 and the 860 because both can communicate changes to an order. The difference is who initiates and why. The EDI 855 is supplier-initiated — a response to the buyer’s PO — while the EDI 860 is buyer-initiated — a request to change an existing PO. Each has different consequences for warehouse scheduling, invoicing, and inventory commitments.

Primary Functional Differences

Understanding the directionality and intent clarifies downstream impacts. The 855 confirms or objects to what the buyer requested; the 860 alters what the buyer wants after the initial order was placed.

• Initiator: 855 is sent by the seller; 860 is sent by the buyer.
• Purpose: 855 confirms acceptance (or not). 860 changes the PO (quantities, dates, cancellations).
• System Impact: 855 updates expectations for inbound receipts; 860 requires the buyer’s PO database and supplier to reconcile and re-acknowledge.

When A Seller Uses An EDI 855

Sellers use the EDI 855 to confirm what they will deliver. Typical scenarios include limited inventory, production delays, or pre-agreed changes such as consolidated shipments. The 855 should clearly indicate acceptance codes and, when partial acceptance occurs, provide backorder visibility and expected ship dates.

• Inventory Constraints: Supplier confirms reduced quantity and supplies a backorder date.
• Schedule Changes: Ship date shifts due to carrier availability or production capacity.
• Rejections: Unacceptable items (regulatory restrictions, discontinued SKUs) are explicitly rejected in the 855.

When A Buyer Sends An EDI 860

Buyers use the EDI 860 to actively change a PO: increase or decrease quantities, change delivery dates, or cancel lines. Once an 860 is sent, the supplier typically responds with an 855 acknowledging the change or noting objections.

• Demand Fluctuations: Buyer reduces quantities due to lower sales velocity or increases due to a promotion.
• Logistics Constraints: Change to consolidate shipments or alter delivery windows for carrier optimization.
• Error Correction: Buyer corrects an incorrect quantity or SKU reported after the original 850 was sent.

Operational Consequences For Warehouses

Each transaction triggers different workflows in the warehouse. An 855 changes inbound expectations based on the supplier’s commitment; an 860 changes the buyer’s desired state and requires supplier concurrence (normally via a subsequent 855).

• Scheduling: 855s drive immediate receiving schedules; 860s may create tentative schedule changes until supplier confirms.
• Inventory Holds: If an 860 reduces expected quantity, warehouses may release allocated stock; if an 855 reduces incoming quantity, substitution or expedited replenishment may be needed.
• Billing: Suppliers will invoice against what they confirm (often what’s in their 855), so finance must reconcile invoice amounts against confirmed quantities.

Practical Example: Sequence And Reconciliation

A buyer sends an 850 for 500 units with requested ship date June 14. The supplier cannot meet that volume and sends an EDI 855 confirming 300 units and backordering 200 for June 28. The buyer, after sales forecasts change, sends an 860 cancelling 100 of the backordered units. The supplier then sends a follow-up 855 acknowledging the 860 and confirming the new totals. Systems must be configured to accept this handshake: the buyer’s ERP updates PO lines on the 860, the supplier updates their shipment plan and the buyer’s WMS adjusts inbound receipts after receiving the supplier’s final 855.

Best Practices For Clear Communication

Establish a documented choreography so buyers and suppliers know expected sequences: 850 → 855 for initial confirmation, 860 for buyer-initiated changes, followed by another 855 to reconfirm. Use agreed qualifiers and codes and ensure both sides process acknowledgments and change orders automatically where possible.

• Choreography Agreement: Document expected sequence of 850, 855, and 860 messages and allowable response times.
• Auto-Reconciliation: Automate reconciliation rules to handle chained changes and avoid double-processing.
• Exception Handling: Treat conflicting acknowledgments (supplier rejects a buyer’s 860) as an immediate escalation to procurement.

In short, the EDI 855 is the supplier’s definitive answer to a purchase order; the EDI 860 is a buyer-initiated request to change that order. Operate both under agreed business rules so warehouses and supply chain systems remain synchronized and exceptions are minimized.