ThePurchase Order (PO)number is a unique identifier assigned by the buyer (consignee) to authorize and track purchases from suppliers. In CLT 4.0, the PO serves as the link between procurement, receiving, and accounts payable processes. It specifies item descriptions, quantities, prices, and delivery terms. Upon receipt, warehouse staff cross-reference incoming goods against the PO to verify accuracy. This ensures order integrity, facilitates accurate billing, and prevents discrepancies. The “pro” number is used by carriers for shipment tracking, not ordering. Effective use of purchase orders contributes to strong control over inbound material flow, cost management, and traceability across the logistics chain.