A receipt is a document of confirmation that goods have been delivered or services performed. The supplier may present a proof of delivery and the buyer may generate a goods receipt note. The goods receipt note is usually part of a three-way match between the purchase order, the invoice and the goods receipt note, and is needed to confirm that the invoice might be paid. When a two-way match occurs, the invoice is matched either to the purchase order or simply to the goods receipt note. In some organisations without an ERP system it can be difficult to encourage end users to confirm that the services have been performed or the goods delivered, and a two-way match reconciling the invoice with the purchase order triggers payment in defined circumstances, such as below a certain value threshold. See also Procurement Controls, Three Way Match and Two Way Match.