Which document is essential for authorizing a purchase?

A purchase order is a critical document for authorizing a purchase because it formally communicates the buyer's intention to procure goods or services. It serves as a legally binding agreement between the buyer and the supplier upon acceptance, detailing specific items, quantities, prices, and terms of delivery. This ensures that both parties have a clear understanding of what is being purchased and the expectations involved, which minimizes the risk of disputes.

In contrast, a bid proposal is often submitted during the bidding process but does not itself authorize a purchase; it is an invitation for sellers to provide their offers. A quote, while useful for understanding costs, is also not sufficient on its own as it does not bind the buyer to a purchase. A contract agreement is typically created after the purchase order and serves a different purpose by outlining the broader terms of engagement but is not the primary document that triggers purchasing authority.