APERAK

The application-level acknowledgement of the EDIFACT family.

Definition

APERAK (Application Error and Acknowledgement Message) is a UN/EDIFACT service message. It tells the sender that a received message (an ORDERS purchase order, an INVOIC invoice…) was accepted or rejected by the receiving business application, with error details where applicable.

Role in the acknowledgement chain

The EDIFACT acknowledgement chain has two levels:

• CONTRL — the syntactic acknowledgement: the interchange is well-formed (or not) per ISO 9735;
• APERAK — the application acknowledgement: the business content was accepted, or rejected with a reason (unknown reference, inconsistent price, invalid item…).

A message can therefore pass CONTRL and still be rejected via APERAK.

Good to know

APERAK is the functional counterpart of the X12 824 Application Advice. In practice many flows skip it and rely on CONTRL alone — at the cost of a blind spot between technical receipt and actual business processing.