X12 864 — Text Message

The 864 is the X12 vehicle for moving a human-readable text: notification, contract, explanation, one-off communication. Designed to be read, not processed by an application.

Purpose

The 864 routes free text over the EDI channel when no dedicated business transaction exists. Typical uses: VAN or partner maintenance notifications, ad-hoc alerts tied to an order, attachment explanations, business-policy change announcements. The text travels in repeated MSG segments and can be classified via an N9 code.

The 864 is not a real-time chat channel: it stays asynchronous and batch like any EDI transaction. For strictly human operational communication, email or a portal remain more relevant; the 864 keeps its place when the EDI audit trail is required (compliance, legal archiving).

Envelope structure

The 864 travels in a functional group TX (Text). Didactic example in release 004010 for a maintenance notification:

ISA*00*          *00*          *ZZ*ACMEHQ        *ZZ*ACMESUPPLIER  *260514*0830*U*00401*000000864*0*P*>~
GS*TX*ACMEHQ*ACMESUPPLIER*20260514*0830*1*X*004010~
ST*864*0001~
BMG*01*01*ALERT-2026-0091~
N9*MM*EDI Service Window 2026-05-15~
MSG*Routine EDI maintenance window. No documents will be processed.~
MSG*Window 22:00 EST 2026-05-15 to 02:00 EST 2026-05-16.~
SE*6*0001~
GE*1*1~
IEA*1*000000864~

The BMG (Beginning Segment for Message) opens with: message type code (alert, information, request…), class, and identifier. The N9 segments add categorisation (subject, urgency). The MSG segments carry the body line by line, free text. A transaction can concatenate several paragraphs via successive MSG segments.

Common segments

• Header — ST, BMG (Beginning Segment for Message), DTM (date).
• Categorisation — N9 loop (Extended Reference Information) with qualifier (SU = Subject, MM = Marketing Message…).
• Body — MSG (Message Text) repeated to the desired length.
• Parties — optional N1 loop to refine sender / receiver beyond ISA/GS IDs.
• Summary — SE.

Common pitfalls

• Segment terminator inside text: if the ~ or * character appears in free text, escape it or pick exotic ISA separators to avoid breaking the receiver's parser.
• Encoding: X12 through release 5010 stays strictly ASCII; accents and non-ASCII characters must be transliterated, or carried in a 6020+ release that accepts UTF-8 via ISA11.
• Good practice: use BMG02 to classify (alert vs information) so the recipient can route the message to the right queue.

Related transactions

• 997 — Functional Acknowledgment
• 824 — Application Advice
• X12 — Hub

Documentation

The code 864 and the name Text Message are public and listed on x12.org/products/transaction-sets. Full BMG01 code lists and the loop structure are in the licensed X12 TR3.