A purchase order change request initiated by a buyer is used to communicate modifications to a previously issued purchase order. The buyer sends this transaction set to the supplier to request changes such as adjustments to quantities, pricing, delivery dates, or line item details. Key segments include the BCH (Beginning Segment for Purchase Order Change), which establishes the change request and references the original purchase order; the POC (Line Item Change) segment, which identifies which line items are being modified; and the CTP (Pricing Information) segment, which allows the buyer to specify revised pricing or cost terms for affected items.

For example, Acme Manufacturing issues a 860 transaction set to TechSupply Corp to modify purchase order PO-2024-5847. The message indicates a reduction in the quantity of part #TS-4490 from 500 units to 300 units on line item 1, with a corresponding adjustment to the unit price from $12.50 to $11.95 per unit to reflect the lower volume. The change includes an updated delivery schedule transmitted in the SCH (Line Item Schedule) segment, with 100 units needed by March 15 and 200 units by April 1. TechSupply Corp receives the 860, reviews the modifications, and sends back an acknowledgment confirming acceptance of the revised terms.