On the Neksus site there are a lot of references to EDI and/or EDIFACT. EDI comes in a lot of forms and sizes. The best known and most used standards are ANSI X12 (also ASC X12) and UN/EDIFACT. These are also the oldest standards which are still used. X12 is a standard which is most used in the US and their trading partners. The rest of the world more or less committed to UN/EDIFACT. Naturally there are exceptions to this rule of thumb.

Both standards have differing syntaxes, and different messages. Some messages are comparable, some do not exist in the other standard. X12 has more than 315 messages, UN/EDIFACT will have less. Their reason to exist is the same: to transport business documents in structured form from 1 computer to the next.

There are other forms and formats like Tradacoms, HIPAA, RosettaNet, SWIFT, VDA, VICS, all with their specifics markets and requirements. To keep this article simple, it will explore UN/EDIFACT in a bit more detail.

UN/EDIFACT stands for United Nations – Electronic Data Interchange For Administration, Commerce and Transport. It is defined and maintained the United Nations to standardize the electronic exchange of commercial documents.

All EDIFACT messages are based on the ISO 9735 standard, in which the syntax units are described.

Information is described in data elements and compound data elements, segments and messages.

Compound data elements are data elements which are connected. Segments contain a segment tag, and 1 or more (compound) data elements.

Messages are constructed by a set of segments in a particular order.

There is a set of special segments called service segments. These usually start with a segment tag beginning with UN (eg, UNH, UNT, etc.) These play a vital role in the structure of a message.

The structure of an EDIFACT message looks like this:

Service String Advice                   UNA  Conditional

+—– Interchange Header           UNB  Mandatory

|  +— Functional Group Header   UNG  Conditional

|  |  +- Message Header                UNH  Mandatory

|  |  |  User Data Segments                         As required

|  |  +- Message Trailer                  UNT  Mandatory

|  +— Functional Group Trailer  UNE  Conditional

+—– Interchange Trailer             UNZ  Mandatory

There are interactive messages (which need to be ping-ponged to a server) and there are batch messages. Messages defined on the highest level are called UNSM: United Nations Standard Message. An UNSM order message must support the order process for ALL industries.

Every year the UN releases 2 updates on the standard. These are named by the year they were released in followed by the letter A (draft) or B (final). For example D96A for the Directory released in 1996 (the draft version) or D01B (released in 2001, the final version)

As you can imagine, the definition is set up very broad, to support a wide range of business types. You will be glad to know that complexity has been greatly reduced by industry organizations wanting to promote the use of these messages in their environment.

EANCOM is such an organization, and they developed a message set for the retail and trade sector. The EANCOM messages, maintained by GS1, are very detailed and tailored to the need of the retail and trade industry. EANCOM has since developed into the most widely used UN/EDIFACT subset and is now also used in other industries such as healthcare, construction and publishing


EDIFACT is used as the Esperanto between computers. Most applications do no “speak” EDIFACT. Applications have their own way of exporting information. Some us flat file, others use XML or other proprietary standards (for example: SAP uses IDOC). To convert to and from EDIFACT from and into a file that an application can use, Neksus offers their translations service. Our computer program uses the incoming EDIFACT messages as input to convert into the format used by the application software (or the other way around: from application to EDIFACT) We can handle the appropriate protocols (like X400, AS2, FTP and other protocols or mailbox systems) to deliver messages from sender to receiver.

Neksus takes out the complexity, so you can rapidly roll out EDI or replace your old EDI system. Contact us today for a quote!