The Complete EDI Document Map: Every Transaction Explained

Why You Need a Document Map

EDI isn't one document — it's a conversation. Retailers and vendors exchange a structured sequence of electronic documents that mirror the physical flow of goods and money. Each document type has a number (called a transaction set), a specific purpose, and a specific place in the order lifecycle.

Most vendors only learn about EDI documents when one fails. This guide gives you the full picture upfront.

The Core Order Lifecycle

Every retail order follows the same basic document flow:

```

Retailer sends PO (850)

→ Vendor acknowledges (855)

→ Vendor ships and sends ASN (856)

→ Retailer sends functional acknowledgment (997)

→ Vendor sends invoice (810)

→ Retailer processes payment

```

Let's break down each one.

EDI 850 — Purchase Order

Direction: Retailer → Vendor When: When the retailer wants to buy something

The 850 is where everything starts. It's the retailer's electronic purchase order, containing:

• Ship-to address — which distribution center or store
• Line items — SKUs, quantities, unit prices
• Dates — requested ship date, must-arrive-by date, cancel-after date
• PO number — the reference that ties every subsequent document together

What You Need to Know

• Every field matters. The ship-to address determines routing. The dates determine your OTIF window. The PO number must appear on every document you send back.
• Some retailers send PO changes as a separate document (EDI 860). Others resend a modified 850. Know which approach your partners use.
• Always validate quantities and item numbers against your inventory before acknowledging.

Key Segments

EDI 855 — Purchase Order Acknowledgment

Direction: Vendor → Retailer When: Within 24 hours of receiving the 850 (for most retailers)

The 855 tells the retailer: "We received your PO and here's what we can do." It's your chance to confirm, reject, or modify the order before shipping.

Response Codes

What You Need to Know

• Walmart expects an 855 within 24 hours. Target within 48 hours. Missing the window can trigger compliance flags.
• If you can only ship 90 of 100 units, say so in the 855 with code AD. Don't acknowledge 100 and then short-ship — that's worse.
• Some vendors skip the 855 entirely. Don't. It's your first chance to set expectations, and retailers track acknowledgment rates as a compliance metric.

EDI 856 — Advance Ship Notice (ASN)

Direction: Vendor → Retailer When: At time of shipment — before the goods arrive

The 856 is the most compliance-sensitive document in the entire EDI flow. It tells the retailer exactly what's in the shipment, how it's packed, and how it's being delivered. The retailer's receiving dock uses it to plan unloading, and their systems use it to automatically receive inventory.

What's in an ASN

The Hierarchical Structure

The 856 is unique among EDI documents because it uses hierarchical levels (HL segments) to describe the physical nesting of a shipment:

```

Shipment

└── Order (PO reference)

└── Pack (Carton 1)

├── Item A — 24 units

└── Item B — 12 units

└── Pack (Carton 2)

└── Item A — 24 units

```

What You Need to Know

• Timing is everything. The ASN must arrive before the physical shipment. If the truck arrives first, the ASN is useless and you'll get chargebacks.
• Accuracy is non-negotiable. If the ASN says 48 units and the carton contains 46, that's a discrepancy — even if the missing 2 were damaged and you had good reason.
• Carton-level detail is required by Walmart, Target, and most major retailers. Each carton needs a unique SSCC-18 identifier that matches the physical GS1-128 label.
• The 856 generates more chargebacks than any other document. Get this one right and half your compliance problems disappear.

EDI 810 — Invoice

Direction: Vendor → Retailer When: After shipment, before payment

The 810 is your electronic invoice. It tells the retailer what you shipped and what they owe. It must match both the original PO (850) and the ASN (856).

The Three-Way Match

Retailers perform a three-way match before paying:

```

PO (850) quantities + prices

↕ must match

ASN (856) shipped quantities

↕ must match

Invoice (810) billed quantities + prices

```

If any of the three disagree, payment gets held and you get a deduction or chargeback.

What You Need to Know

• Invoice in the retailer's unit of measure. If the PO says 144 eaches, your invoice says 144 eaches — even if you internally track by the case.
• The PO number on your invoice must exactly match the PO number from the 850. Character for character.
• Some retailers require one invoice per PO. Others allow consolidated invoices. Know your partner's rules.
• Net payment terms are typically specified by the retailer, not negotiated per invoice.

Key Segments

EDI 997 — Functional Acknowledgment

Direction: Both ways When: Immediately upon receiving any EDI document

The 997 is the "read receipt" of EDI. It confirms that a document was received and could be parsed. It does not confirm business acceptance — just technical receipt.

Response Codes

What You Need to Know

• A 997 saying "Accepted" means the document was syntactically valid. It doesn't mean the retailer agrees with the content.
• If you send an ASN and never get a 997 back, something went wrong with transmission. Investigate immediately.
• Most EDI platforms handle 997s automatically. You shouldn't need to manually generate these.

Less Common But Important Documents

EDI 860 — Purchase Order Change

Direction: Retailer → Vendor When: Retailer needs to modify a PO after the original 850

Changes to quantities, dates, or items. Your system should be able to detect changes and flag them for review rather than blindly processing the original PO.

EDI 846 — Inventory Inquiry/Advice

Direction: Vendor → Retailer When: Regular inventory reporting

Some retailers (especially Amazon and Walmart for certain programs) require periodic inventory level reports so they can optimize replenishment orders.

EDI 820 — Payment Order/Remittance Advice

Direction: Retailer → Vendor When: When the retailer issues payment

Details what's being paid, what deductions were taken, and which invoices are covered. This is where you discover chargebacks — often weeks after the original shipment.

EDI 753/754 — Routing Request and Response

Direction: 753 Vendor → Retailer, 754 Retailer → Vendor When: When the retailer arranges freight (collect shipments)

You request a routing, the retailer responds with carrier and pickup details. Required for collect programs at most major retailers.

The Document Timeline

For a typical Walmart order, here's the expected timeline:

Common Mistakes Across All Documents

1. PO number mismatch — Using a reformatted or truncated PO number. It must be character-exact across all documents.
2. UOM inconsistency — Mixing eaches and cases between documents. If the PO says eaches, every document says eaches.
3. Date format errors — EDI uses YYYYMMDD (20260328), not MM/DD/YYYY. Simple but breaks parsing.
4. Missing required segments — Each retailer has specific required fields beyond the standard. A valid X12 document can still fail a retailer's compliance check.
5. Stale trading partner data — Retailer changes their EDI qualifier or ID and your system is still sending to the old one.

How JayChris EDI Handles This

JayChris EDI manages the full document lifecycle automatically. When a PO arrives, it parses the 850, generates the 855 acknowledgment, converts units of measure, creates the ASN at shipment time, generates a matching invoice, and handles all 997 acknowledgments — with retailer-specific formatting for each trading partner.

You don't need to memorize segment codes or worry about document timing. The system handles the conversation so you can focus on fulfilling orders.