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 · Projects and construction

CONEST Establishment of contract

The UN/EDIFACT message a client uses to issue the contractual bill of quantities after tendering, as the basis for all later work and payment.

Sent by
Client or client's representative
Received by
Appointed contractor
Standard
UN/EDIFACT · Batch message
X12 equivalent
No direct equivalent

What is the EDIFACT CONEST message?

CONEST is the UN/EDIFACT establishment of contract message. The directory explains that, when tendering is complete, the client or its representative must formally establish and issue the contractual bill of quantities, which becomes the contractual basis for all future work and payment.

The contractual bill may differ from the tender after negotiation. Issuing it as a message gives both parties one agreed data set that later progress (CONQVA) and payment (CONPVA) messages refer to. Changes after this point are handled as variations to the contract.

How the EDIFACT CONEST message worksDiagram of the UN/EDIFACT CONEST Establishment of contract message. Client or client's representative sends it to appointed contractor. It usually follows CONTEN. It is usually followed by CONQVA and CONPVA. Inside the UNB and UNH envelopes, the directory D.21A requires, in the start of message: BGM (Beginning of message), RFF (Reference) and DTM (Date/time/period) and body and segment groups: UNS (Section control). 3 conditional segment groups are listed by their trigger segment.How the EDIFACT CONEST message worksEstablishment of contract: who sends it, where it fits and what the directory marks mandatory1 WHERE IT FITSUSUALLY FOLLOWSCONTENTenderCONESTSENDERClient or client'srepresentativeRECEIVERAppointed contractorCONTRL syntax report back, if agreedUSUALLY FOLLOWED BYCONQVAQuantity valuationCONPVAPayment valuation2 WHAT DIRECTORY D.21A REQUIRESInterchange: sender and recipient IDsUNB … UNZMessage CONESTUNH … UNTSTART OF MESSAGEBGMBeginning of messageRFFReferenceDTMDate/time/periodBODY AND SEGMENT GROUPSUNSSection control+ 3 conditional groups, starting with:INDBIIBlue 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 directory D.21A listing for CONEST. Your trading partner's implementation guide adds itsown requirements.
How the EDIFACT CONEST message worksDiagram of the UN/EDIFACT CONEST Establishment of contract message. Client or client's representative sends it to appointed contractor. It usually follows CONTEN. It is usually followed by CONQVA and CONPVA. Inside the UNB and UNH envelopes, the directory D.21A requires, in the start of message: BGM (Beginning of message), RFF (Reference) and DTM (Date/time/period) and body and segment groups: UNS (Section control). 3 conditional segment groups are listed by their trigger segment.How the EDIFACT CONESTmessage worksEstablishment of contract: who sends it, whereit fits and what the directory marks mandatory1 WHERE IT FITSUSUALLY FOLLOWSCONTENTenderCONESTSENDERClient or client'srepresentativeRECEIVERAppointedcontractorCONTRL syntax report back, if agreedUSUALLY FOLLOWED BYCONQVAQuantity valuationCONPVAPayment valuation2 WHAT DIRECTORY D.21A REQUIRESInterchange: sender and recipient IDs(UNB … UNZ)Message CONEST (UNH … UNT)START OF MESSAGEBGMBeginning of messageRFFReferenceDTMDate/time/periodBODY AND SEGMENT GROUPSUNSSection control+ 3 conditional groups, starting with:INDBIIBlue 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 directory D.21A listing for CONEST.Your trading partner's implementation guide adds itsown requirements.

How to read this diagram: the top row shows who sends CONEST, to whom, and which messages usually come before and after it. The lower part shows what the directory D.21A itself requires: the envelopes around CONEST 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, such as an industry subset or a partner’s own guide, usually makes some conditional groups mandatory, restricts the codes and may use an older directory.

Expand diagram Download SVG

When it is used

  • Issuing the contractual bill of quantities
  • Recording negotiated changes to the tender
  • Setting the baseline for valuations

Where it fits in the message flow

Usually follows CONTEN Tender
This message CONEST Establishment of contract
Usually followed by CONQVA Quantity valuationCONPVA Payment valuation

Structure

Mandatory segments in CONEST (directory D.21A)

In UN/EDIFACT directory D.21A, the CONEST message has 110 segment positions arranged in 34 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, not your trading partner’s: each partner’s message implementation guide names the directory it uses, often an older one such as D.96A or D.01B where the structure can differ, makes some conditional segments mandatory and restricts the codes.

  • UNH
  • BGM
  • RFF
  • DTM
  • UNS
  • UNT

Practical example

CONEST in practice

After negotiation, a client awards a bridge contract with revised rates for a few items. It sends the contractor a CONEST with the contractual bill of quantities. Monthly progress valuations then reference the contract items and rates from this message.

Implementation

Implementation considerations for CONEST

  • Make the contractual bill the single reference for later valuations.
  • Record negotiated changes clearly against the tender.
  • Keep item references unchanged from the tender where possible.
  • Archive the message with the signed contract.

How ECOM helps

Automate CONEST with ECOM

Industry

Industrial Manufacturing

Distributor, OEM customer and supplier integration for industrial manufacturers.

Solution

Procure-to-Pay Automation

Automate purchasing, receiving and supplier invoicing across EDI, portals and documents.

Solution

Financial Document Automation

Automate invoices, remittances, payment files and bank statements from capture to posting.

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

Related messages

Related projects and construction messages

All 14 projects and construction messages

Need help with CONEST?

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

Request a Demo Contact us