What is EDI 864? Uses, Format & Example (2026 Guide)

Most EDI transaction sets - the 850 purchase order, the 810 invoice, the 856 advance ship notice, are rigid by design. They follow strict X12 schemas because they have to be machine-readable. But every supply chain eventually generates communication that doesn’t fit a schema: an invoice number that doesn’t match, a missing pack list, a one-off explanation to AP. That’s what EDI 864, the Text Message transaction set, exists for. This guide breaks down what EDI 864 is, when retailers like Walmart require it, how it’s structured, and how it compares to 997 and 824.

Read more: EDI Document Types Explained: 850, 810, 856, & More

What is EDI 864?

The EDI 864 (Text Message Transaction Set) is used to send free-form, non-structured messages between trading partners. Unlike other EDI transaction types, such as

• 850 (Purchase Order)
• 810 (Invoice)
• 856 (Advance Ship Notice)

that uses strict data structures and syntax rules and is used mostly for automated, system-to-system processing; the 864 is meant to be more human-readable, making it suitable to communicate explanations and clarifications, communicate contacts, or any other one-time communication within the business context that doesn’t really fit into any structured dataset like the above.

Typical Uses

• To communicate explanations and clarifications within the business context: The EDI 864 can be used to deliver detailed instructions or provide clarification related to specific transactions or supply chain events.
• To exchange contracts.
• To communicate time sensitive updates: The EDI 864 can be used to share any urgent updates, such as an order shipment delay.
• To send brief communications: It’s useful for short messages, like reminders about upcoming meetings or actions.
• To reach partners without full EDI support: The EDI 864 can still be delivered to trading partners who lack EDI capabilities, since it can be sent as an email attachment.
• Notifications about policy updates, any updates in business procedure.
• Administrative messages: The EDI 864 can be used to communicate compliance warnings or error messages.

When to Use and Avoid the Use of 864

Common Retailer Use Cases

Retailers often require 864 messages when:

• There’s a dispute or an error tied to another document: an invoice mismatch, to inform about missing shipment details etc.
• A supplier needs to provide additional context not supported in structured transactions.
• Communication must remain within EDI for auditability and compliance.

When 864 should not be Used

Retailers should avoid 864 when:

• A structured transaction already exists: using 810 instead of describing an invoice manually.
• When the message flow is automated with systematic processing.

• A more appropriate transaction exists, such as:

  • 997 for acknowledgments
  • 824 for application-level errors

864 is generally used when the message is not much structured but the communication should be within the EDI format.

Walmart and retailer requirements

Large retailers often have strict EDI compliance requirements, and Walmart is one of the most notable examples. Walmart specifically requires suppliers to support the EDI 864 transaction set for invoice-related error notifications and dispute communication. According to Walmart’s supplier EDI specifications, the 864 is considered one of the core transaction sets suppliers should implement alongside the 810 (Invoice), 816 (Organizational Relationships), 820 (Payment Order/Remittance Advice), 850 (Purchase Order), 856 (Advance Ship Notice), and 997 (Functional Acknowledgment). Suppliers are expected to validate and support these transactions before going live with Walmart’s EDI program. Proper handling of 864 messages is important because invoice disputes, payment delays, and compliance-related communication are often transmitted through this transaction set.

Read more: Walmart’s EDI Requirements: A Guide for Suppliers

864 EDI message structure

An EDI 864 message follows standard X12 envelope structure with a flexible message body.

Core 864 Segments

• BMG (Beginning Segment for Text Message)

  BMG segment defines the beginning of the text message transaction set. It includes details like the purpose of the EDI transaction set and the message subject and the type of the message the EDI file contains.

• DTM (Date/Time Reference)

  Indicates any date time related data, related to the message content.

• N1 Loop (Name Information)

  Identifies sender/receiver parties.

• MIT Loop

  The most important part of the 864 text message. It contains the actual message content.

  • MIT (Message Identification)

    The segment that identifies the beginning of a specific message within the 864 text message EDI file. It contains the subject of the message.

  • MSG (Message Text)

    The free-form text the sender intends to communicate with the receiver.

When to use 864 vs. 997 vs. 824

To choose the best EDI type for a specific scenario, it is crucial to understand the difference between the types, 864, 997, and 824. These EDI types focus on different distinction functionalities in the business communication workflow.

The EDI 997 (Functional Acknowledgment)

Is used to confirm that an EDI document has been successfully received by the intended recipient. Once the recipient receives an EDI message, it sends the 997 functional acknowledgement to the sender after an EDI syntax level validation to inform the sender if the transaction set was accepted or rejected.

The EDI 824 (Application Advice)

Another acknowledgment that goes one step further by reporting errors found within the content of a transaction set. It provides structured validation feedback, making it useful when a transaction fails business rules or contains incorrect or missing data, for example, an invoice rejected due to incomplete fields even though it was syntactically correct.

The EDI 864 (Text Message)

As discussed is used for free-form communication with a flexible structure compared to the others and is typically used for business-level messaging such as clarifications, explanations, or disputes. When information doesn’t fit neatly into a structured transaction, the 864 provides a way to communicate it in a human-readable format.

Even though all these three types are responses to a received EDI document, they serve distinct purposes.

Read more: Difference Between the 4 Types of EDI Acknowledgments

EDI 864 Example

Imagine a received Invoice EDI file contains a wrong PO number. The sample 864 EDI document sent back would look something like this.

ISA*00*          *00*          *ZZ*SENDERID       *ZZ*RECEIVERID     *230331*0004*U*00401*000000001*0*P*>~
GS*TX*SENDERID*RECEIVERID*20230331*000400*864000005*X*004010~
ST*864*0001~
BMG*00*ERROR NOTIFICATION~
DTM*097*20230331~
N1*FR*ABC INDUSTRIES~
N1*TO*XYZ SUPPLIES~
MIT*Ref_123*Invoice Error Notification~
MSG*Please correct the Invoice Number 00682426 as it does not match our records.~
MSG*Resend to the attention of AP Department.~
SE*9*0001~
GE*1*864000005~
IEA*1*000000001~

Here the EDI document has the subject ‘ERROR NOTIFICATION,’ and it contains a single free-form message with the subject ‘Invoice Error Notification.’

Common Errors and How to Fix Them

Compared to more organized transaction sets, the EDI 864 can be challenging to work with, mostly because it contains free-form text meant for human interpretation rather than computer processing, and if they are not automatically generated, they can be more error-prone compared to other EDI types. This adaptability presents a number of typical difficulties. For instance, transactions may fail if necessary segments like BMG or ST are absent, and messages may be difficult to read or process if MSG segments are badly constructed, such as when text is excessively lengthy or incorrectly divided. ISA/GS segment mismatches could cause the entire transaction set to be rejected. If unsupported characters are used, even character encoding issues can result in unexpected failures.

Read more: Overcoming 5 Common EDI Implementation Issues

There are more general operational difficulties in addition to these validation problems. The unstructured nature of the 864 makes it challenging to maintain consistency and clarity in communications, which raises the possibility of misunderstandings between trade partners. It also takes more work to integrate 864 processing into current systems, particularly for teams without an established EDI infrastructure. It’s not easy to set up, maintain, and train teams to handle these messages. Another level of accountability is added by making sure that transmission is secure and that partner criteria are met. All things considered, although the 864 offers freedom, treating it carefully is necessary to prevent misunderstanding, delays, and processing errors.

Read more: EDI Generator: Getting past the dreaded “EDI validation failed

Generating and Transmitting 864s with EDI Generator

Generating and transmitting an 864 is easier than ever with EDI Generator, without the complexity of handling detailed EDI specifications, segment structures, and element rules typically associated with EDI documents.

With EDI Generator, you can define your EDI specification once and reuse it as a boilerplate, allowing you to quickly generate 864 documents without rebuilding the structure each time.

Generate an 864 in minutes with EDI Generator - free trial, no credit card required.

EDI 864 FAQ

What is EDI 864 used for?

EDI 864 is used to send free-form text messages between trading partners when the communication doesn’t fit a structured transaction set. Common uses include invoice error notifications, shipment exception notes, contract communications, time-sensitive updates, and administrative messages such as policy changes or compliancewarnings. It’s particularly useful for clarifications tied to other EDI documents that already have a transaction reference.

Is EDI 864 mandatory for Walmart suppliers?

Yes. Walmart’s standard supplier EDI specification requires support for EDI 864, primarily for invoice error notifications. Suppliers must complete validation testing for 864 alongside 810, 816, 820, 850, 856, and 997 before going live. Failing to handle a Walmart 864 properly can delay invoice payments and trigger chargebacks.

What’s the difference between EDI 864, 997, and 824?

EDI 997 is a functional acknowledgment confirming a document was received and passed syntax validation. EDI 824 reports application-level errors when a document passes syntax but fails business rules. EDI 864 is a free-form text message for human-readable communication that doesn’t fit either acknowledgment. Use 997 for “did it arrive,” 824 for “what’s wrong with the content,” and 864 for everything else.

What segments does an EDI 864 contain?

A standard EDI 864 contains the ISA/GS envelope, an ST segment to open the transaction set, a BMG (Beginning Segment for Text Message), DTM for date/time, N1 loops to identify sender and receiver, and one or more MIT loops containing MSG segments with the free-form message body. The SE/GE/IEA segments close the transaction, group, and interchange.

Can EDI 864 be sent by email instead of AS2?

Technically, yes! EDI 864 files can be sent as email attachments to partners without full EDI infrastructure, since the format is X12 text. However, for auditability and trading-partner compliance, retailers like Walmart require 864 over the same secure channel as the rest of the EDI stack, usually AS2. Sending 864 over AS2 also gives you a non-repudiation receipt via MDN.