972-836-7750 Request a demo Talk to an expert
Talk to an expert Request a demo Call sales 972-836-7750

EDIFACT message guide · Control and acknowledgments

CONTRL Syntax and service report message for batch EDI

The UN/EDIFACT service message that acknowledges or rejects a received interchange, group or message and reports syntax errors.

Sent by
Receiver of an interchange
Received by
Sender of the interchange
Standard
UN/EDIFACT · Service message
X12 equivalent
997 Functional Acknowledgment

What is the EDIFACT CONTRL message?

CONTRL is the UN/EDIFACT syntax and service report message for batch EDI. It syntactically acknowledges or rejects, with error indications, a received interchange, functional group, message or package. It can also be used simply to confirm that an interchange was received.

CONTRL answers whether a transmission arrived and could be read, not whether its business content was acceptable; that is the job of APERAK. Partners agree in advance whether CONTRL is required, and the sender requests it in the interchange header. Missing or negative CONTRLs are a prompt to investigate before a business process stalls.

How the EDIFACT CONTRL message worksDiagram of the UN/EDIFACT CONTRL Syntax and service report message for batch EDI message. Receiver of an interchange sends it to sender of the interchange. It usually starts the exchange. Inside the UNB and UNH envelopes, the syntax version 4 service directory requires, in the start of message: UCI (Interchange response). 2 conditional segment groups are listed by their trigger segment.How the EDIFACT CONTRL message worksSyntax and service report message for batch EDI: who sends it, where it fits and what the directory marksmandatory1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeCONTRLSENDERReceiver of aninterchangeRECEIVERSender of theinterchangeUSUALLY FOLLOWED BYNo business reply expected2 WHAT SYNTAX VERSION 4 REQUIRESInterchange: sender and recipient IDsUNB … UNZMessage CONTRLUNH … UNTSTART OF MESSAGEUCIInterchange responseBODY AND SEGMENT GROUPS+ 2 conditional groups, starting with:UCMUCFBlue box: mandatory segment group. Conditional groups are listed by the trigger segment that starts them; a group is sent only when its data applies.Conditional segments outside groups are not drawn.Structure: mandatory segments and groups in the UN/EDIFACT syntax version 4 service directory listing for CONTRL. Your trading partner's implementationguide adds its own requirements.
How the EDIFACT CONTRL message worksDiagram of the UN/EDIFACT CONTRL Syntax and service report message for batch EDI message. Receiver of an interchange sends it to sender of the interchange. It usually starts the exchange. Inside the UNB and UNH envelopes, the syntax version 4 service directory requires, in the start of message: UCI (Interchange response). 2 conditional segment groups are listed by their trigger segment.How the EDIFACT CONTRLmessage worksSyntax and service report message for batchEDI: who sends it, where it fits and what thedirectory marks mandatory1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeCONTRLSENDERReceiver of aninterchangeRECEIVERSender of theinterchangeUSUALLY FOLLOWED BYNo business reply expected2 WHAT SYNTAX VERSION 4 REQUIRESInterchange: sender and recipient IDs(UNB … UNZ)Message CONTRL (UNH … UNT)START OF MESSAGEUCIInterchange responseBODY AND SEGMENT GROUPS+ 2 conditional groups, starting with:UCMUCFBlue box: mandatory segment group. Conditionalgroups are listed by the trigger segment thatstarts them; a group is sent only when its dataapplies. Conditional segments outside groups arenot drawn.Structure: mandatory segments and groups in theUN/EDIFACT syntax version 4 service directorylisting for CONTRL. Your trading partner'simplementation guide adds its own requirements.

How to read this diagram: the top row shows who sends CONTRL, to whom, and which messages usually come before and after it. The lower part shows what the syntax version 4 service directory itself requires: the envelopes around CONTRL and the segments and segment groups it marks mandatory. Conditional groups are listed by their trigger segment rather than drawn in full. This is the directory's minimum, not a trading partner's requirement: a message implementation guide usually makes some conditional groups mandatory, restricts the codes and may use an older directory.

Expand diagram Download SVG

When it is used

  • Confirming receipt of an interchange
  • Rejecting interchanges or messages with syntax errors
  • Reporting unsupported functionality in a received message

Where it fits in the message flow

This message CONTRL Syntax and service report message for batch EDI

No other message routinely comes directly before or after CONTRL; it is exchanged when the business event occurs.

Structure

Mandatory segments in CONTRL (syntax version 4)

In syntax version 4 of the service directory (ISO 9735), the CONTRL message has 10 segment positions arranged in 5 segment groups. These are the segments and segment groups marked mandatory at message level, in order; a mandatory group is shown with the segment that starts it. Segments inside conditional groups are needed only when the group is used. This is the directory’s requirement; earlier syntax versions define the message differently, and partners agree which version they use. This structure comes from one published copy of the directory and has not been independently verified: confirm it before you build a map.

  • UNH
  • UCI
  • UNT

Practical example

CONTRL in practice

A supplier sends an interchange with 40 invoices to a customer and requests acknowledgement in the UNB header. The customer's translator finds that one message has a missing mandatory segment. It returns a CONTRL accepting the interchange but rejecting that one message, with the segment position and error code, and the supplier corrects and resends it.

Implementation

Implementation considerations for CONTRL

  • Agree whether CONTRL is required and at which level (interchange or message).
  • Monitor for missing acknowledgements within an agreed time.
  • Check which syntax version the partner uses, since CONTRL differs between versions.
  • Do not treat a positive CONTRL as business acceptance.

How ECOM helps

Automate CONTRL with ECOM

Solution

EDI Integration

Exchange X12 and EDIFACT documents with partners and integrate them directly with your ERP.

Solution

B2B Integration

Connect every customer, supplier, carrier and bank across EDI, API, file and portal channels.

Service

Mapping and Translation

Map development and maintenance for X12, EDIFACT, XML, JSON, flat files and ERP formats.

Compare X12 and EDIFACT, or see answers to general questions in the EDI FAQ.

Need help with CONTRL?

ECOM maps, tests and monitors EDIFACT messages for your trading partners and integrates them with your ERP.

Request a Demo Contact us