Non-posting accounts occur in your accounting records and must be kept closely watched and maintained to keep your orders and order history accurate. Two types of non-posting accouts are purchase orders and sales orders. Let's begin with purchase orders. Purchase orders are orders you are making for your goods/items (otherwise known as inventory). They are non-posting since the order does not have any dollar value attributed to the accounting records UNTIL the inventory is received. Once the inventory is received, the corresponding items on the purchase order are reduced from the purchase order, and received into inventory at the good(s)/item(s) value and when all items are received, the purchase order is closed.
Another type of non-posting order, the sales orders, are orders from customers not yet in stock. They are non-posting since the items are not yet received. Once the customer's item(s) are received, the sales order is invoiced (moved to a sales invoice for the customer) which means items that have been reserved for that customer received on the order thus invoicing the cutsomer. At this point, posting is now done in the inventory, sales, cost of goods sold and accounts payable accounts.