EDI 850 (Purchase Order) is an X12 transaction set to place a purchase order for goods or services with a vendor as per customary and established business and industry practice.

EDI 855 (Purchase Order Acknowledgement) is an X12 transaction set used by sellers to send an acknowledgment to a buyer's purchase order as per customary and established business and industry practice. It can also be used to notify vendor-generated orders, which helps a buyer know if the seller has or will ship the order per pre-agreed terms.

EDI 810 (Invoice) is an X12 transaction set to send billing information for rendered goods and services as per customary and established business and industry practice.