EDI Basics

A plain-English introduction to Electronic Data Interchange — what it is, how X12 documents are structured, and how trading partners communicate.

What is EDI?

EDI (Electronic Data Interchange) is the computer-to-computer exchange of business documents between companies in a standardized electronic format. Instead of printing a purchase order, faxing or emailing it, and waiting for a human to re-enter the data, EDI lets two systems exchange that purchase order automatically — in seconds, with no manual intervention.

EDI is used for Purchase Orders, invoices, shipping notices, payments, forecasts, and dozens of other business documents. It is mandatory for doing business with most large retailers and many logistics providers.

The X12 Standard

ANSI X12 (commonly called just "X12") is the EDI standard used in the United States and Canada for virtually all industries — retail, healthcare, transportation, manufacturing, and finance. x12port is built specifically around the X12 standard.

X12 is maintained by the Accredited Standards Committee X12 (ASC X12). Documents are organized into transaction sets, each identified by a 3-digit number (e.g., 850 = Purchase Order).

Document Structure

Every X12 document follows a strict hierarchical envelope structure:

ISA*00*          *00*          *ZZ*SENDERID       *ZZ*RECEIVERID     *230101*1200*^*00501*000000001*0*T*:~
GS*PO*SENDERID*RECEIVERID*20230101*1200*1*X*005010~
ST*850*0001~
BEG*00*SA*PO-12345**20230101~
... (transaction set segments) ...
SE*15*0001~
GE*1*1~
IEA*1*000000001~

Key ISA fields

Transaction Sets

The most commonly used X12 transaction sets across industries:

Connection Methods

Trading partners exchange EDI documents over several types of connections. The method is typically dictated by the larger partner (usually a retailer or large manufacturer).

The 997 Acknowledgment

The 997 Functional Acknowledgment is the X12 document you send back to confirm receipt of a functional group. It is mandatory in virtually all trading partner agreements and must be returned promptly — typically within 24 hours.

A 997 can indicate:

• A (Accepted) — the functional group was received and is syntactically valid
• E (Accepted with Errors) — accepted but contains notes or minor issues
• R (Rejected) — the functional group failed validation and must be resent

Failing to send 997s on time is a common source of chargebacks and compliance violations. Use the 997 Acknowledgment Tracker to stay current.

Test vs. Production

Before going live with a new trading partner, you exchange test documents to verify your setup. During testing, ISA15=T (Test). Once both sides confirm everything is working, you switch to ISA15=P (Production) and begin live exchanges.

x12port's API key system mirrors this: sandbox keys (xp_test_) for development, live keys (xp_live_) for production.