EDI 850, 855, 856, 810: the purchase order cycle, explained

Four documents carry one order from "we want this" to "pay us." Buyers send one, sellers send three, and a fifth document confirms receipt of each. Here's the whole cycle, who sends what, and which pieces actually get enforced in trading-partner agreements.

The cycle at a glance

850: the order

The buyer's system emits the purchase order with PO number, dates, ship-to, and PO1 line items carrying both their part numbers and (usually) yours. Everything downstream references this PO number.

855: the acceptance

This is the document behind the phrase "EDI PO acceptance." The 855 answers the 850 line by line: accepted as-is, accepted with changes (price correction, new ship date, substituted item), backordered, or rejected. Large buyers put teeth on it — an 855 due within 24 or 48 hours, with chargebacks for silence. It's also where price disputes surface early: if your acknowledgment reprices a line, the buyer's system flags it before anything ships, not after the invoice lands.

856: the ship notice

The advance ship notice describes the physical shipment in a hierarchy: shipment, orders inside it, cartons or pallets inside those, items inside those, with carrier and tracking. Receiving docks scan against it. In retail relationships the 856 is the most chargeback-prone document of the four: late, missing, or mismatched ASNs cost real money.

810: the invoice

The seller's bill, tied to the PO number from the 850. The buyer's AP system matches 810 against 850 (and often the 856 and receiving data, the classic three-way match) and pays only when they agree. Clean 855s and 856s upstream are what make 810s pay on time.

The asymmetry nobody mentions

Look at the sender column again: the buyer sends one document, the seller sends three. EDI compliance is mostly the seller's workload, which is why big buyers mandate it and small sellers groan. Per-partner mapping, testing, VAN fees, and chargeback exposure all land on the fulfillment side.

When the cycle runs on email instead

Below the volume where per-partner EDI setup pays back, the same cycle happens anyway, just unstructured: the 850 is a PDF on email, the 855 is "got it, ships Thursday," the 856 is a tracking number pasted into a reply, the 810 is a QuickBooks invoice. The steps didn't disappear; the structure did, and someone retypes the PDF into the books. That intake step is what SideQuest automates for QuickBooks distributors: the emailed PO becomes a drafted Estimate with lines matched to your catalog, and the "got it" reply becomes a one-click Gmail draft. Background on the fallback pattern in when EDI orders arrive by email.

FAQ