When is a purchase order considered accepted?

A purchase order is considered accepted when the seller acknowledges receipt of the order and confirms their intent to fulfill it, typically through a written confirmation or an invoice. This acceptance can also occur when the seller begins to process the order or delivers the goods/services. In some cases, acceptance may be implied by the seller's conduct, such as shipping the items. It is important that the terms of the purchase order align with the seller's acceptance to avoid disputes.