Glossary

Definitions for common EDI terms, X12 segment names, acronyms, and x12port-specific terminology.

A – C

850 — Purchase Order: The foundational EDI transaction. A buyer (retailer, distributor) sends an 850 to a supplier to place an order for goods. Contains item numbers, quantities, unit prices, requested delivery dates, and ship-to addresses.
855 — Purchase Order Acknowledgment: Sent by the supplier in response to an 850. Confirms acceptance, communicates back-orders, substitutions, or line-level rejections. Required by most large retailers within 24–48 hours.
856 — Advance Ship Notice (ASN): Notifies the buyer that goods have shipped. Includes carton and pallet structure, SSCC barcode values, tracking numbers, and contents. Must be sent before the truck arrives at the buyer's DC. Late or inaccurate ASNs are a major source of retail chargebacks.
810 — Invoice: Electronic invoice from supplier to buyer. Must reconcile against the original 850 and the 856 in the buyer's three-way match process. Discrepancies trigger chargebacks or payment holds.
820 — Payment Order / Remittance Advice: Sent by the buyer to communicate payment detail and which invoices the payment covers.
997 — Functional Acknowledgment: Acknowledges receipt and syntactic validity of an EDI functional group. Required for every exchange. A 997 with AK5*R indicates rejection — the sender must correct and resend.
AS2 — Applicability Statement 2: A communication protocol for EDI over HTTPS. Uses digital signatures and receipts (MDNs) to ensure secure, non-repudiable document exchange. Required by most large US retailers.
ASN — Advance Ship Notice: See 856.
Chargeback: A penalty fee charged by a trading partner (usually a retailer) when an EDI compliance requirement is violated — such as a late ASN, missing 997, or incorrect document format. Chargebacks are a primary driver for EDI compliance.

D – G

DC — Distribution Center: A retailer's or distributor's warehouse where inbound shipments are received, sorted, and sent to stores.
EDI — Electronic Data Interchange: Computer-to-computer exchange of business documents in a standardized format. Eliminates paper documents and manual re-keying of data between trading partners.
Envelope: The hierarchical wrapper structure of an X12 interchange: ISA/IEA (interchange) → GS/GE (functional group) → ST/SE (transaction set).
GS — Functional Group Header: The X12 segment that opens a functional group. One ISA interchange can contain multiple GS/GE functional groups, each containing one or more transaction sets of the same type.

I – M

Implementation Guide: A trading partner-specific document that describes exactly which X12 segments and elements are required, optional, or not used in their EDI relationship. Always request a partner's implementation guide before beginning setup.
ISA — Interchange Control Header: The outermost envelope segment of an X12 document. Contains sender/receiver ISA IDs, test/production flag (ISA15), version number, and interchange control number.
ISA ID (also: Interchange Sender/Receiver ID): A unique identifier for your company or trading partner within EDI exchanges. Appears in ISA06 (sender) and ISA08 (receiver). Must be provided to every new trading partner.
ISA Qualifier: A 2-character code that defines the type of ISA ID. Common values: 01 = DUNS, 08 = UCC EDI Comm ID, 12 = Phone, 14 = DUNS+4, ZZ = Mutually Defined (most common).
ISA15: The test/production indicator in the ISA segment. T = Test, P = Production. Must be P for all live exchanges.
Mapping: The process of defining which source fields correspond to which target fields when converting documents between formats (e.g., internal JSON → X12 850). Mapping rules define field-level translations and transformations.
MDN — Message Disposition Notification: An AS2 receipt. When your partner receives an AS2 transmission, they return an MDN confirming delivery. Synchronous MDNs are returned immediately; asynchronous MDNs come back later via a separate HTTP call.

P – S

PO — Purchase Order: See 850.
Segment: A logical unit of data in an X12 document, identified by a 2–3 character segment identifier (e.g., BEG, PO1, CTT). Segments are terminated by a tilde (~) and elements within a segment are separated by asterisks (*).
SFTP — Secure File Transfer Protocol: A common EDI connection method where files are placed in agreed inbox/outbox directories on a remote server. Simpler to set up than AS2 but asynchronous — you poll for new files rather than receiving real-time notifications.
SSCC — Serial Shipping Container Code: An 18-digit barcode assigned to a shipping unit (carton or pallet). SSCCs appear in the 856 ASN and on GS1-128 labels applied to shipments. Required by most major retailers.
ST — Transaction Set Header: The segment that opens a single transaction (e.g., one Purchase Order) within a functional group. Contains the 3-digit transaction set identifier code and a control number.

T – Z

Trading Partner: Any business with which you exchange EDI documents — a retailer, distributor, supplier, 3PL, or carrier. Each trading partner has their own ISA ID and implementation requirements.
Transaction Set: A specific type of EDI document identified by a 3-digit number (850, 856, 810, etc.). Each transaction set has a defined structure of required and optional segments and elements.
Three-Way Match: The buyer's reconciliation process that matches the Purchase Order (850), the Advance Ship Notice (856), and the Invoice (810). All three must agree on quantities and prices for payment to be released automatically.
UPC — Universal Product Code: 12-digit barcode on retail products. Appears in 850 and 856 line items as the product identifier.
VAN — Value-Added Network: A third-party intermediary that routes EDI documents between trading partners. You connect to the VAN once and they handle routing to all your partners. Common VANs: SPS Commerce, TrueCommerce, GS1 US, DiCentral, 1 EDI Source.
X12: The ANSI X12 EDI standard used in North America for retail, healthcare, logistics, manufacturing, and finance. Maintained by the Accredited Standards Committee X12 (ASC X12). The standard x12port is built around.