UN/EDIFACT (the United Nations rules for Electronic Data Interchange for Administration, Commerce and Transport) is a UN recommended standard and probably the most widely used structured business and government message standards in the world.

The UN/EDIFACT standard provides a set of syntax rules to structure data which contains directories of data elements, composite data elements, segments, and messages; and there are conventions for placing messages in an "envelope" which identifies the sender and receiver and other attributes of a transmission.

As UN/CEFACT messages are a superset of many collaborations, it is common practice to develop and publish subsets of these messages into message implementation guidelines. Organisations such as WCO, GS1, AIAG and Odette have contributed significantly to the continued development of UN/EDIFACT and once published, they will subset the messages into guidelines for specific sectors in their areas of interest.

While its use is still growing steadily, UN/CEFACT and other Standards Organizations has seen the need to provide alternatives. Most of these new standards are based on new requirements to have semantic data models and be based on technologies such as Core Component Technical Specification CCTS. These standards are xml based and are more familiar to implementers who are involved in Internet technologies and may therefore have the potential to be the predominant means of exchanging trade documents in the next decade.
For example the UN/EDIFACT INVOICE message is widely used by large companies, particularly in retailing. UN/EDIFACT is developed by UN/CEFACT and its popularity is continuing to grow every year. EDIFACT syntax rules were first registered as an ISO standard - ISO 9735 in 1987.

UN Recommendations 25 and 26, adopted in 1995, advise on the use of EDIFACT in government messaging. These recommendations were to assist governments in the adoption of messaging using EDIFACT. As XML standards were not available at this stage, no reference is made to them.