# EDI 865 PO Change Acknowledgment/Request: Seller Guide
> How the EDI 865 works: a supplier acknowledging a buyer's 860 change or proposing a seller-initiated change. Covers the BCA and POC segments and the change loop.
The EDI 865 is the Purchase Order Change Acknowledgment/Request, Seller-Initiated. A supplier sends it to confirm or reject a buyer's 860 change request, or to propose its own change, such as a substitution or a revised ship date. It is the supplier-side counterpart to the buyer's 860 and closes the change loop.
**The EDI 865 is how a supplier responds to a change, or starts one.** When a buyer sends an [860 Purchase Order Change](/guides/edi/860-purchase-order-change), the supplier replies with an 865 to accept or reject it line by line. The supplier can also originate an 865 to propose its own change, like a backorder, a substitution, or a later ship date. Without it, change requests go unanswered and shipments drift out of sync with what the buyer expects.
This guide covers the two ways the 865 is used, its segments, where it sits in the change loop, and how a supplier handles one cleanly.
## What Is an EDI 865?
**An EDI 865 is the Purchase Order Change Acknowledgment/Request, Seller-Initiated, defined by the [ASC X12 standards body](https://x12.org/). It lets a supplier acknowledge a buyer's change to a purchase order, or initiate a change of its own, line by line.** It mirrors the buyer's 860 from the seller's side of the relationship.
Authoritative references for 865 implementation:
- The [X12.org Transaction Sets reference](https://x12.org/products/transaction-sets) defines the BCA and POC segment structure used across 865 implementations
- [GS1 US](https://www.gs1us.org/standards) governs the UPC and GTIN identifiers used on each changed line
**Who sends it?** The supplier (seller).
**When is it sent?** Either in response to a buyer's 860 change request, or on the supplier's own initiative before fulfillment when something about the order has to change.
**Why does it matter?** It closes the loop on changes. A change nobody acknowledged is a change nobody can rely on, and unacknowledged changes are a common source of disputes, short shipments, and chargebacks.
## The Two Ways an 865 Is Used
The transaction name carries both jobs:
- **Change acknowledgment.** The buyer sent an [860 Purchase Order Change](/guides/edi/860-purchase-order-change). The supplier replies with an 865 that accepts the change, rejects it, or accepts it with detail, line by line. This tells the buyer whether the revised order will ship as changed.
- **Seller-initiated change request.** Nothing came from the buyer, but the supplier needs to change the order: a line is on [backorder](/glossary/backorder), an item must be substituted, or the ship date slips. The supplier sends an 865 to propose the change and waits for the buyer to accept it.
The acknowledgment code in the header is what distinguishes "I accept your change" from "I am proposing a change."
## Key Segments Explained
Here are the segments you will work with in an 865 transaction set:
| Segment | Name | Purpose |
|---------|------|---------|
| **ST** | Transaction Set Header | Identifies the start of the 865 and assigns a control number |
| **BCA** | Beginning Segment for PO Change Acknowledgment | The purpose code, the acknowledgment type (accept, reject, accept with change), the original PO number, and the change date |
| **N1** | Name | Identifies the buyer, supplier, and ship-to parties |
| **POC** | Line Item Change | The changed line: change action code, quantity, price, and the item, by buyer and supplier part number |
| **REF** | Reference Identification | Carries the original PO and any change-order references |
| **CTT** | Transaction Totals | Number of line items in the acknowledgment |
The **BCA** sets the intent for the whole document, and each **POC** carries one line's change action: accept, reject, change quantity, substitute, or cancel.
## Where the 865 Sits in the Change Loop
The 865 completes the purchase-order change cycle:
1. **[850 Purchase Order](/guides/edi/850-purchase-order)** - Buyer places the order
2. **[855 PO Acknowledgment](/guides/edi/855-purchase-order-acknowledgment)** - Supplier confirms the original order
3. **[860 PO Change](/guides/edi/860-purchase-order-change)** - Buyer requests a change (quantity, date, cancel a line)
4. **865 PO Change Acknowledgment** - Supplier accepts or rejects the change, or proposes its own
5. **[856 Ship Notice / ASN](/guides/edi/856-ship-notice)** - Supplier ships against the agreed, current order
Together the 855 and 865 are the supplier's two acknowledgments: the 855 answers the original 850, and the 865 answers any change to it.
## How Suppliers Handle 865s Cleanly
Change handling is where a lot of small suppliers lose the thread, because an 860 lands in an EDI mailbox and someone has to decide, line by line, whether the order can still ship as changed and then send a matching 865.
OrderSync reads inbound 860 change requests, lines them up against the original order, and surfaces exactly what changed for a quick accept-or-reject decision, then generates the matching 865. The same flow lets a supplier originate a seller-initiated 865 for a backorder or substitution. It outputs valid X12 to the EDI client your trading partner already polls, with no ERP integration required to start. Try the [free EDI inspector](/edi-inspector) on one of your own change documents, or [book a 15-minute walkthrough](/book-call) to see the 860 and 865 cycle end to end.
## Frequently Asked Questions
### What is an EDI 865 used for?
The 865 is used by a supplier to acknowledge a buyer's purchase order change (an 860), or to propose a change of its own, such as a substitution or a revised ship date. It confirms, line by line, whether the changed order will ship as requested.
### What is the difference between an EDI 860 and an EDI 865?
The 860 is buyer-initiated: the buyer requests a change to a purchase order. The 865 is the supplier's response to that change, or a supplier-initiated change request. The 860 asks; the 865 answers or proposes.
### What is the difference between an EDI 855 and an EDI 865?
The 855 acknowledges the original purchase order. The 865 acknowledges a change to it. A supplier sends an 855 once for the 850, then an 865 for any subsequent change.
### Is an EDI 865 required?
It depends on the trading partner. Many retail and manufacturing programs that use the 860 change process require a matching 865 so both sides agree on the current state of the order before it ships.