997 vs 855: two acknowledgments, two very different promises
One says “we can read your file.” The other says “we will ship your order.” Mixing them up is how orders go missing.
ST*997*0001~ AK1*PO*1042~ AK2*850*0001~ AK5*A~ AK9*A*1*1*1~ SE*6*0001~
ST*855*0001~ BAK*00*AD*4500012345*20261002~ PO1*1*120*EA*8.40**UP*012345678905~ ACK*IA*120*EA~ CTT*1~ SE*6*0001~
Both documents start with “acknowledgment”, both travel back to the sender, and both often arrive within minutes of the order. That is where the resemblance ends.
Side by side
| 997 | 855 | |
|---|---|---|
| Confirms | The file arrived and its syntax is valid | You accept, change or reject the order |
| Sent by | Whoever received the file | The supplier |
| Answers | Any transaction: 850, 856, 810… | Only the 850 |
| Line detail | None | Each line’s status and quantity |
| Written by | Software, automatically | You, from your stock and capacity |
Three differences that trip people up
A 997 is automatic
It is generated by software as soon as a file is read, and checks the envelope and syntax described in the X12 file format. No person has looked at the order yet.
An 855 is a commitment
It tells the buyer, line by line, what you will ship. Many retailers measure your fill rate against it.
They have different deadlines
A missing 997 is chased within hours. The 855 deadline is in the partner’s guide, often one to two business days.
The short answer
You almost always need both: the 997 so the buyer knows the file arrived, the 855 so they know what is coming.
Questions
Does a 997 mean my order was accepted?
No. A 997 only says the file arrived and its syntax was valid. Whether the order is accepted, changed or rejected is the job of the 855.
Do I have to send an 855?
Only if your partner requires it, and many retailers do. Their implementation guide says so, along with the deadline.
What if the order changes after the 855?
The buyer sends an 860 and you answer with an 865: see how purchase orders change.
Keep reading
All articles →Both acknowledgments, handled
Weredi sends and reconciles 997s automatically and builds your 855 from the purchase order it answers.