Final answer:
Sales orders and estimates are considered non-posting entries in accounting as they do not lead to a direct change in the accounting books until they turn into financial transactions.
Step-by-step explanation:
Sales orders and estimates are examples of non-posting entries because no accounting entry is made. In the accounting process, non-posting entries are documents that are prepared as part of the sales process but do not directly affect the financial statements because they do not result in immediate revenue or expense recognition. An estimate might be given to a customer to outline potential costs of a job or project, while a sales order is an internal document that instructs the preparation of goods for shipment; neither leads to a direct change in the accounting books until they result in an invoice, which is a posting transaction. These documents are crucial in the planning and order stages but are only recognized in accounting when they become financial transactions.