An invoice is a document issued by a vendor to a buyer for goods or services provided. It includes details such as the products or services, their quantities, price, taxes, total amount due, and payment terms.
Invoice with PO: An invoice with a Purchase Order (PO) references a specific PO number, indicating that the goods or services billed correspond to the items ordered in the PO. This ensures payment aligns with the prior purchase agreement.
Invoice without PO: An invoice without a Purchase Order (PO) does not reference any specific PO number. This typically occurs when a purchase is made directly, without a formal requisition, or when the vendor does not require a PO for processing. The invoice is processed independently of any prior PO.