A method and system are provided for dynamic purchase ordering functionality in a business information system according to one embodiment of the present invention. The dynamic purchase ordering functionality receives a purchase order confirmation from a supplier and notifies the purchaser. If the supplier provides a deviating quantity in the purchase order confirmation (i.e., the supplier confirmed quantity is different than the purchaser ordered quantity), a dynamic availability of the product and/or service with the deviating quantity is determined and presented to the purchaser along with the purchase order confirmation in order to assist the purchaser in responding to the supplier's purchase order confirmation and to provide the purchaser with an integrated set of data in order to allow the purchaser greater flexibility and efficiency in responding to the supplier's purchase order confirmation. In this manner the purchase ordering system may be enhanced from the purchaser's perspective.