What is the EDI 855 - Purchase Order Acknowledgment? 
The EDI 855 Purchase Order Acknowledgment is used by sellers to confirm receipt and acceptance, rejection, or modification of an EDI 850 Purchase Order eliminating the need to call or fax a confirmation.
The Purchase Order Acknowledgment (855) contains all information normally associated with a purchase order and like other acknowledgment transactions, closes the loop on communication by ensuring both buyer and seller are aligned on product, quantity, price, and delivery terms.
The 855 can indicate that the order was accepted, rejected or accepted with changes and may even suggest changes to orders, establishing it as a critical transaction in the order-to-cash cycle.
How does PartnerLinQ use the EDI 855 - Purchase Order Acknowledgment?
PartnerLinQ leverages the 855 to streamline supplier responses to buyer orders. It supports full, partial, or modified acceptance of purchase orders, automatically updating ERP and OMS systems. PartnerLinQ also provides visibility into rejections and reasons, ensuring buyers can quickly adjust forecasts and replenishment plans. This integration helps minimize delays and disputes in procurement cycles.
What responses to the EDI 855 - Purchase Order Acknowledgment are expected/sent?
The EDI 855 functions as the formal response to an EDI 850 Purchase Order. Common responses include:
- AC: Acknowledge – With Detail and Change
- AK: Acknowledge – No Detail or Change
- RJ: Reject – No Detail
- RD: Reject with Detail – requires rejection details
Subsequent adjustment details may be communicated by the buyer to the seller through “change by refresh”, the 860 (Purchase Order Change) or by the seller with shipment details in the 856 (Advance Ship Notice).
What does the EDI 855 - Purchase Order Acknowledgment support?
The 855 supports synchronized procurement by ensuring both trading partners agree to the terms of an order before fulfillment. It provides a legal and audit trail, demonstrates compliance with buyer mandates, and reduces costly errors by clarifying accepted quantities, pricing, and ship dates.
What are the Key Features of the EDI 855 - Purchase Order Acknowledgment?
- Confirms,
rejects, or modifies purchase orders - Provides line-item level acceptance/rejection
- Communicates dates, pricing, and delivery terms
- Integrates with ERP and supply chain planning tools
- Enhances visibility into supplier commitments
What is the Purpose of the EDI 855 - Purchase Order Acknowledgment?
The purpose of the EDI 855 is to allow sellers to electronically confirm acceptance, rejection, or proposed changes to purchase orders, thereby reducing manual interventions, accelerating order cycles, and ensuring compliance.
What Information is Included in the EDI 855 - Purchase Order Acknowledgment?
Typical information carried in the 855 includes:
- PO number and reference identifiers
- Acknowledgment type (BAK02)
- Item details and quantities (PO1)
- Rejection or modification reasons
- Delivery and scheduling details (DTM, TD5)
- Allowances, charges, and terms (SAC, ITD)
What are the Essential Components of the EDI 855 - Purchase Order Acknowledgment?
| Segment | Description |
|---|---|
| ST | Transaction Set Header |
| BAK | Beginning Segment for Purchase Order Acknowledgment |
| REF | Reference Identification |
| N1-N4 | Name and Address segments |
| PO1 | Baseline Item Data |
| PID | Product/Item Description |
| SAC | Allowances/Charges |
| TD5 | Carrier Details |
| MSG | Message Text |
What are the Common Segments Included in the EDI 855 - Purchase Order Acknowledgment?
| Segment | Description |
|---|---|
| BAK | Acknowledgment information |
| REF | PO and reference identifiers |
| N1 | Buyer, Seller, Ship-to parties |
| PO1 | Line items |
| SAC | Allowances/Charges |
| PRF | Purchase Order references |
| PID | Item descriptions |
What Status Codes are used with the EDI 855 - Purchase Order Acknowledgment?
Key acknowledgment codes (BAK02):
- AC = Acknowledge, order accepted
- RJ = Reject, order not accepted
- RD = Reject with Detail, partial acceptance/rejection at line level
What Reason Codes are used with the EDI 855 - Purchase Order Acknowledgment?
Reason codes may appear in:
- SAC04 to explain allowance or charge reasons
N9/MSG to provide rejection or modification explanations
Examples: damaged goods, incorrect pricing, discontinued item.
What Use Cases does the EDI 855 - Purchase Order Acknowledgment?
- Retail
replenishment cycle (confirming POs) - Manufacturing supplier responses
- Distribution and wholesale compliance with buyer mandates
- Exception management through rejections or partial acceptance
What are the Benefits of the EDI 855 - Purchase Order Acknowledgment?
- Ensures alignment on order details before shipment
- Reduces disputes and costly returns
- Improves forecasting and planning accuracy
- Provides electronic audit trail for compliance
How efficient is the EDI 855 - Purchase Order Acknowledgment?
The EDI 855 - Purchase Order Acknowledgment reduces cycle times by automating supplier order responses and eliminating the need to call or fax a confirmation.
How Compliant is the EDI 855 - Purchase Order Acknowledgment?
The EDI 855 - Purchase Order Acknowledgment supports buyer/supplier compliance programs, trade agreements and mandates.
What is the Format of the EDI 855 - Purchase Order Acknowledgment?
The EDI 855 - Purchase Order Acknowledgment follows ASC X12 formatting rules for Purchase Order Acknowledgment.
How Accurate is the EDI 855 - Purchase Order Acknowledgment?
The EDI 855 - Purchase Order Acknowledgment improves the accuracy of procurement to pay cycles by clarifying accepted and rejected order and items, standardizing data exchange protocols for consistency and enhancing performance.
What are the Limitations of the EDI 855 - Purchase Order Acknowledgment?
The EDI 855 requires careful mapping between buying and selling systems and personas particularly when it comes to the more complex scenarios (e.g., partial acceptance with substitutions), and scenarios which require detection, alerting, notifications, or custom workflows and configuration.
Are Guidelines & Sample Files for the EDI 855 - Purchase Order Acknowledgment available?
Yes. PartnerLinQ provides sample EDI 855 - Purchase Order Acknowledgment Transaction and implementation guides through its Support and Guideline Management Team.
Sample EDI 855 implementation guides illustrate both inbound and outbound flows, segment layouts, and valid data examples and support testing and partner onboarding. Customized specification documents for use in on boarding and technical development are available upon request.
PartnerLinQ provides:
- EDI 855 - Purchase Order Acknowledgment transaction implementation guide
- Sample payloads
- Qualification and testing maps
- Error handling and best-practice notes

What are the Basic Questions for EDI Integration with the EDI 855 - Purchase Order Acknowledgment?
- Are there Samples and Specs available?
- What Acknowledgment Type codes must be supported?
- How are acceptance codes managed?
- How are rejection codes managed?
- How will rejections and modifications be communicated?
- Are line-item rejections supported?
- Are partial acceptances allowed?
- How should ERP systems handle amended orders
- Is there any scenario related to price or carrier information change in 855?
- What is the trigger for Order confirmation?
- How are cancellation scenarios managed?
- Are we canceling the complete Order?
- Are we canceling individual lines?
- Which SAC allowance/charge codes must be included?
How should ERP/OMS handle partial acknowledgments? - Is customization specific to the Customer?
- Are there any rejection reason codes that require transformation?
- Are there SLAs for the 855?
- Is there any Scenario where the EDI Order is modified after the confirmation?
What Business Level Workflow does the EDI 855 - Purchase Order Acknowledgment support?
- Buyer issues an EDI 850 Purchase Order.
- Seller reviews and responds with an EDI 855.
- Seller either accepts, rejects, or modifies the PO.
- Buyer reviews the acknowledgment.
- Adjustments are finalized through an 860 or shipment proceeds with an 856.
- Invoice (810) closes the cycle.

What are the Best Practices for using the EDI 855 - Purchase Order Acknowledgment
- Respond promptly with 855 acknowledgments.
- Use correct BAK02 status codes (AC, RJ, RD).
- Provide clear rejection reasons in N9/MSG segments.
- Align SAC allowances/charges with contracts.
- Maintain consistency with buyer compliance guides.
What Transactions are associated with the EDI 855 - Purchase Order Acknowledgment?
| Transaction | ANSI X12 – Role/Description |
|---|---|
| 850 | 850 Purchase Order |
| 855 | 855 Purchase Order Acknowledgement |
| 860 | 860 Purchase Order Change |
| 856 | 856 Advance Ship Notice |
| 810 | 810 Invoice |
| 997 | 997 Functional Acknowledgment |
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