X12 865 — Purchase Order Change Acknowledgment

The 865 is the supplier's response to an 860 change request. For each modified line it states explicitly whether the change is accepted, partially accepted, or rejected.

Purpose

The 865 plays two interesting roles. First and most common: respond to an 860 from the buyer, line by line, saying whether the requested change is accepted. Second, rarer but useful: initiate a change on the supplier side (for instance, notifying the buyer that a line cannot be delivered on the planned date because of a supply incident). In this second role, the 865 is the X12 equivalent of a seller-initiated change.

The BCA segment (Beginning Segment for PO Change Acknowledgment) carries an acknowledgment code that clarifies the nature of the 865: AC = With Detail and Change, AK = No Detail, RD = Reject With Detail, etc. Workflow-wise, receiving an 865 closes the conversation opened by the 860 and freezes the up-to-date operational contract.

Envelope structure

The 865 travels in a PE functional group (PO Change Acknowledgment). Here is a didactic 865 responding to the 860 on order PO78901: the first change is accepted, the second rejected.

ISA*00*          *00*          *ZZ*ACMEVENDOR    *ZZ*ACMERETAIL    *260516*1500*U*00401*000001001*0*P*>~
GS*PE*ACMEVENDOR*ACMERETAIL*20260516*1500*1*X*004010~
ST*865*0001~
BCA*04*AC*PO78901*001*20260516**20260513~
REF*VR*VENDOR-CHG-552~
N1*VN*ACME VENDOR INC*92*VEND001~
POC*1*QC*1*EA*9.99**UP*012345678905~
ACK*IA*1*EA**UP*012345678905~
POC*2*DI*5*EA*19.50**UP*012345678912~
ACK*IR*0*EA**UP*012345678912~
CTT*2~
SE*10*0001~
GE*1*1~
IEA*1*000001001~

The BCA reuses the BAK mechanics from the 855: function code, acknowledgment code, original PO number, change sequence number, date. Each POC is paired with an ACK carrying the line status (IA = Item Accepted, IR = Item Rejected, IB = Item Accepted with Quantity Change…).

Common segments

• Header — ST, BCA (Beginning Segment for PO Change Acknowledgment), REF, DTM.
• Parties — N1 loop for Vendor (VN), Buyer.
• Lines — POC loop with ACK (status), PID, SCH, DTM.
• Summary — CTT, AMT, SE.

When you'll see it

• Retail — used when a buyer attempts to change after acceptance. The retailer waits for the confirmation before adjusting its allocation plan.
• Manufacturing — particularly useful when the supplier hits a difficulty (supply shortage, quality issue).
• Distribution — less common than a plain 855, but key for post-acceptance modifications.

Related transactions

• 850 — Purchase Order
• 855 — Purchase Order Acknowledgment
• 860 — Purchase Order Change Request
• 870 — Order Status Report

Documentation

The code 865 and the name Purchase Order Change Acknowledgment are public and listed on x12.org/products/transaction-sets. The exhaustive acknowledgment-code list and the segment-by-segment detail live in the proprietary Implementation Guides (TR3); ediverse.io does not redistribute them.