Creating Purchase Order Acknowledgement (EDI 855)

The Purchase Order Acknowledgment (EDI 855) is a transaction sent by a supplier to a buyer to confirm receipt of a Purchase Order (EDI 850) and state whether the order is accepted, rejected, or accepted with changes (such as different quantities, prices, or ship dates).

This guide walks you through two methods of creating an EDI 855 in the EDI Generator, with a focus on creating one from scratch using a real-world Walmart partner scenario.

Pre-populating from a Received PO

If you have already received the Purchase Order in the EDI Generator, you do not need to enter all the fields manually:

  1. Navigate to the received PO in your Inbox or PO (or Retail > PO) list.
  2. Open the PO formatted view, or click the Generate button at the end of the PO row.
  3. Click Generate PO Ack.
  4. The system will load the EDI 855 editor pre-populated with details like the buyer’s PO number, partner identification, dates, and line items.

For more details, see Processing Purchase Orders (EDI 850).

Creating an EDI 855 from Scratch

If you need to initiate a Purchase Order Acknowledgment manually without a received PO, follow these steps using our sample Walmart scenario.

Scenario Context

  • Partner: Walmart
  • PO Number: 1252448667
  • PO Date: 2026-09-01
  • Department Number: 00054
  • Current Scheduled Ship Date: 2026-09-10

Start Acknowledgment Creation

  1. In the side menu, navigate to PO Ack (or Retail > PO Ack if nested).
  2. Click the Create button in the top-right corner.
  3. Select your partner (e.g., Walmart) from the dropdown.
  4. The EDI editor will load the structure for the 855 document.

For a detailed guide on how the EDI Editor interface works (including how to add segment iterations, use Basic or Advanced loop modes, and locate validation errors), see Create New EDI File.

Create PO ACK

Enter Beginning Segment details (BAK Segment)

The BAK segment contains the purpose of the transaction and references the original PO. Click on the BAK segment row in the editor to open its fields:

  • Transaction Set Purpose Code (BAK01): Select 00 (Original) to accept/respond, or 16 (Proposed) if proposing changes.
  • Acknowledgment Type (BAK02): Select the response status:
    • AD – Acknowledge with Detail, No Change (accepting the order as-is).
    • AC – Acknowledge with Detail and Change (accepting with quantity/price modifications).
    • RJ – Rejected - No Detail (declining the entire order).
  • Purchase Order Number (BAK03): Enter the 10-digit PO number (e.g., 1252448667).
  • PO Date (BAK04): Select the exact date specified as the purchase order date in the corresponding purchase order.

Enter Reference Information (REF Segment)

The REF segment transmits critical reference codes required by Walmart.

  1. Click the REF segment row to expand.
  2. Select the Reference Identification Qualifier (REF01):
    • Select DP for Department Number.
  3. Enter the department number in Reference Identification (REF02).
  4. Click Add Row if you need to add other references, such as Vendor Number (IA, 9 digits) or Customer Order Number (CO).

Add Extended Reference Identifier (N9 Loop - Optional)

The N9 Loop is used to specify additional reference identifiers (such as promotion codes, special instructions, or contract numbers) along with associated messages:

  1. Locate the N9 Loop in the editor and expand it.
    • Reference Identification Qualifier (N901): Select the qualifier code (e.g., ZZ for Mutually Defined or other custom qualifiers).
    • Reference Identification (N902): Enter the actual reference identifier value.

Configure Party Details (N1 Loop)

You must specify who the message is for (Buying Party) and who is sending it (Supplier).

  1. Click the N1 Loop to expand it.
  2. Buying Party (BY):
    • Entity Identifier Code (N101): Select BY (Buying Party).
    • Name (N102): Enter Walmart.
    • Identification Code Qualifier (N103): Select UL (Global Location Number - GLN).
    • Identification Code (N104): Enter the 13-digit GLN for the Walmart purchasing entity.
  3. Supplier Party (SU):
    • Click Add Loop Iteration to add a second N1 entry.
    • Entity Identifier Code (N101): Select SU (Supplier).
    • Name (N102): Enter your supplier name.

Configure Line Items (PO1 Loop)

Expand the PO1 loop to enter the line item details.

  1. Baseline Item Data (PO1):
    • Quantity (PO102): Enter the quantity accepted or proposed.
    • Unit or Basis for Measurement (PO103): Select the correct unit of measurement (such as EA for Each).
    • Unit Price (PO104): Enter the item unit price (e.g., 12.50).
    • Product/Service ID Qualifier (PO106): Select IN (Buyer’s Item Number).
    • Product/Service ID (PO107): Enter the 9-digit item code assigned by Walmart.
    • Product/Service ID Qualifier (PO108): Select UP (UCC-12).
    • Product/Service ID (PO109): Enter the 12-digit UPC code.
  2. Line Item Acknowledgment (ACK Loop):
    • Line Item Status Code (ACK01): Select the status for this item:
      • IA – Item Accepted (order line is accepted as-is).
      • IR – Item Rejected (order line is cancelled/declined).
      • IQ – Item Accepted - Quantity Changed (proposing different quantities).
    • Quantity (ACK02): Enter the quantity corresponding to the response status.
    • Unit of Measure (ACK03): Select the unit of measurement (such as EA).
    • Line Item Dates (DTM Segment under ACK Loop - Optional):
      • If you need to specify a scheduled shipping or delivery date for this specific line item, click to expand the DTM segment inside the ACK Loop:
      • Date/Time Qualifier (DTM01): Select 068 (Current Scheduled Ship) or 017 (Estimated Delivery).
      • Date (DTM02): Select the date.

Set Transaction Totals (CTT Segment)

By default, the EDI Generator automatically calculates the totals for the CTT segment to prevent manual counting errors:

  • Number of Line Items (CTT01): Auto-calculated based on the total number of PO1 loops added.
  • Hash Total (CTT02): In this Walmart 855 scenario, only CTT01 is used. However, if a partner’s EDI definition includes the CTT02 element, the EDI Generator will automatically calculate and populate the hash total (the sum of all item quantities) here as well.

If you need to manually override this value:

  1. Expand the CTT segment row.
  2. Uncheck the Enable Auto Calculation checkbox.
  3. Manually enter or edit the Number of Line Items (CTT01) field.

The segments and element rules detailed above represent a sample Walmart 855 specification scenario. Depending on your partner, the required qualifiers, loops, pattern validations, and mandatory elements can vary. The EDI Generator automatically aligns the editor form fields and validation rules to match whichever partner definition you select.

Validate, Save, and Send

  1. Once all details are filled, click the Validate and Save button in the top-right corner.
  2. The EDI Generator will check your document against the syntax and validation rules defined in the Walmart 855 specification.
  3. If there are validation errors, correct the pointed out segments and re-validate.
  4. Once the validation is successful, click Send to transmit the 855 PO Acknowledgment to Walmart over AS2/SFTP.

Once you acknowledge the order, the next step in the cycle is packing the goods and generating the shipping documents. See Creating Advance Ship Notices (EDI 856) for instructions on the shipment notice, and Creating Invoices (EDI 810) for requesting payment.