The 855: small document, strict clock
The 855 Purchase Order Acknowledgment is your formal "yes, we'll ship that" — sent back after every 850. It's the simplest document in the loop and the easiest one to be late with.
What it says
At minimum: which PO you're acknowledging (BAK segment referencing the PO number) and your response per line (ACK segments): accepted, accepted with changes (quantity/date/price differences), or rejected. Acknowledging with silent differences is how suppliers accidentally commit to quantities they can't ship — every later document (856,810) gets reconciled against what you acknowledged.
Timing
Retailer guides set an acknowledgment window (commonly within 24 hours of the 850). Late or missing 855s show up on your compliance scorecard even when everything ships perfectly — it's the cheapest scorecard point to protect.
The practical failure modes
| Failure | Consequence |
|---|---|
| 855 never sent (PO sat unread) | Scorecard hit; retailer assumes non-confirmation |
| Acknowledged quantities you can't ship | Short-ship shows up in the three-way match later |
| Wrong PO number referenced | Orphaned acknowledgment; PO still shows unconfirmed |
Where this fits in FluentEDI
The free viewer makes the reading half instant. Generated 855s from the parsed 850 (one click: "acknowledge all lines as ordered") are on the roadmap right behind the 856 generator — same engine, simpler document.