What Is an EDI 855 Purchase Order Acknowledgment?
The EDI 855 is the X12 transaction set a supplier sends in response to a buyer's 850 purchase order. It confirms the order was received and tells the buyer whether the supplier will ship exactly what was ordered, ship with changes (different quantities, substitutions, revised dates), or reject one or more line items. For most retailers, an accurate 855 is a hard compliance requirement, not optional.
EDI 855 Acknowledgment Type Codes
The BAK02 element communicates the supplier's response to the entire PO, and each PO1 line can carry its own line-level acknowledgment status (ACK01). Common codes:
- AC - Accept the order exactly as submitted.
- AD - Accept with detail changes (quantity, price, date, or substitution).
- RJ - Reject the entire order.
- RD - Reject specific line items, accept the rest.
- IA - Item accepted at line level.
- IB - Item backordered.
- IR - Item rejected at line level.
- IC - Item accepted with changes (quantity or date).
EDI 855 Segments and Structure
A standard 855 mirrors the structure of the originating 850 so the buyer can match it line-by-line:
- BAK - Acknowledgment type, original PO number, and PO date.
- REF - Vendor and department references that tie back to the 850.
- DTM - Confirmed ship date and delivery date.
- N1 / N3 / N4 - Confirmation of ship-to and bill-to parties.
- PO1 - Each accepted, changed, or rejected line item.
- ACK - Line-level acknowledgment status and reason codes.
- CTT / SE - Line count and transaction set trailer.
EDI 855 Timing Requirements
Most major retailers require the 855 within 24 hours of receiving the 850, and some (Walmart, Target) enforce tighter windows for fast-moving categories. Late or missing 855s are treated as non-acknowledgment, count against vendor scorecards, and in some programs trigger automatic order cancellation.
How Yoke Handles the EDI 855 for You
Yoke auto-generates the 855 from your ERP's order confirmation, validates inventory and pricing before sending, applies the right BAK and ACK codes for each retailer's spec, and monitors transmission against each partner's timing window so a missed acknowledgment never quietly costs you a scorecard point.
Frequently Asked Questions
Quick answers to the questions buyers and suppliers ask most about this transaction.
- What is an EDI 855? The EDI 855 is the X12 Purchase Order Acknowledgment. A supplier sends it in response to an 850 to confirm whether the PO will be shipped as ordered, accepted with changes, or rejected.
- What is the difference between an EDI 997 and an EDI 855? The 997 only confirms the technical receipt of the 850 file - the equivalent of a delivery receipt. The 855 is the business response, confirming the supplier actually accepts and will fulfill the order.
- When does the EDI 855 need to be sent? Most large retailers require the 855 within 24 hours of receiving the 850. Some fast-moving programs enforce shorter windows. Late 855s typically result in scorecard penalties or order cancellation.
- What are the EDI 855 acknowledgment codes? At the header level: AC (accept), AD (accept with changes), RJ (reject), RD (reject with detail). At the line level: IA (accepted), IC (accepted with change), IB (backordered), IR (rejected).
- Is the EDI 855 required? Yes - for almost every major retailer. Walmart, Target, Amazon, Home Depot, and most grocery chains require an 855 for every 850 and treat missing acknowledgments as a compliance violation.