What Is EDI 855 (Purchase Order Acknowledgment)?
Also known as: X12 855, PO acknowledgment, order acknowledgement EDI, POA
Definition
The EDI 855 is the X12 transaction set a supplier sends in reply to a customer's 850 purchase order. It states whether each line is accepted, changed or rejected, with the confirmed quantity, price and delivery date.
EDI 855 (Purchase Order Acknowledgment) Explained
The 855 is a business-level reply, different from the 997 or 999 functional acknowledgment. The 997 only says the file was received and syntactically valid. The 855 says what the supplier will actually do with the order. A customer can have a perfectly valid 997 and still receive an 855 that rejects half the lines.
The BAK segment in the header sets the status for the whole order, and ACK segments at line level state the status per line. Typical codes are accepted without change, accepted with changes, and rejected. When the supplier changes something, the 855 carries the new quantity, price or date so the customer's buyer can see the difference against the original PO.
In ERP terms, the 855 is produced when a customer order is entered or confirmed. In SyteLine this is the Customer Order line with its promise date and release status. In NetSuite it is the sales order after approval. In Infor LN it is the sales order line with its confirmed delivery date. A common design is to create the sales order automatically from the 850, then send the 855 after credit and availability checks complete.
Not every customer asks for an 855, and some accept silence as agreement. Where it is required, an automated 855 prevents the buyer from chasing status by phone and gives the customer an early warning of late delivery, which feeds their own planning.
Why It Matters
- It gives the customer an early, structured warning when a delivery date or price will differ from the PO.
- Automating it reduces order status calls and emails to the customer service team.
- It exposes whether the supplier's ERP actually confirms dates from real availability or just copies the requested date.
- Some OEM scorecards measure acknowledgment timeliness and accuracy.
In Practice
A customer sends an 850 for 1,000 pieces due on the 15th. The supplier's order entry runs availability and finds 800 pieces can ship on the 15th and 200 on the 22nd. The 855 returns line 1 as accepted with changes, with two schedule lines. The customer's buyer sees the split in their PO screen and can decide to expedite the balance or accept it.
Frequently Asked Questions
What is the difference between an 855 and a 997?
A 997 or 999 only confirms the file arrived and was valid. The 855 is the supplier's business reply that accepts, changes or rejects the order.
Is the 855 mandatory?
It depends on the trading partner's guide. Many customers require it, others do not.
What is the 865?
The 865 is the Purchase Order Change Acknowledgment, sent in reply to an 860 PO change request, while the 855 replies to the original 850.
Which ERP data drives the 855 dates?
The confirmed promise or ship date on the customer order line. If that date is only a copy of the request date, the 855 adds no information.
Related Terms
EDI (Electronic Data Interchange)
EDI (Electronic Data Interchange) is the computer-to-computer exchange of business documents such as purchase orders, invoices, and shipping notices between trading partners in a standardized structured format, without human intervention.
EDI 850 Purchase Order
The EDI 850 is the ANSI X12 transaction set used to transmit a purchase order electronically from a buyer to a supplier, carrying header terms, ship-to and bill-to parties, and line item details such as quantity, price, and product identifiers.
EDI 856 (Advance Ship Notice)
The EDI 856 is the X12 transaction set a supplier sends to a customer before a shipment arrives. It lists what is in the shipment, how it is packed and labeled, and which purchase order lines it fulfils, so the receiver can plan dock work and receive by scan.
ATP (Available to Promise)
ATP (available to promise) is the portion of inventory and scheduled production not yet committed to existing customer orders, calculated by date so order entry can quote a delivery a customer can rely on.
Data Mapping
Data mapping is the process of defining how each field in a source system corresponds to a field in a target system, including the transformation rules, value translations, default values, and conditional logic needed to move data correctly between them.
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