How do we know that an EDI transmission has been received?

The receiver of an EDI transmission is responsible for sending back an administrative EDI document called a Functional Acknowledgment (FA). In its most common form, the FA simply identifies the received transmission by its sender-assigned control number, document type (e.g., PO, invoice, etc.), and number of documents sent. It is the sender’s responsibility to follow with the intended receiver if an acknowledgment has not been received, usually within 1 business day.