An image processing apparatus capable of communicating with an external apparatus via a network registers a transfer setting containing an ID for identifying destination information stored in the external apparatus to transfer received image data, acquires the destination information corresponding to the ID contained in the registered transfer setting from the external apparatus, and transfers the received image data using the acquired destination information. When the destination information cannot be acquired, a cause why the destination information cannot be acquired is determined, and if the cause why the destination information cannot be acquired is due to a communication error with the external apparatus, the registered transfer setting is not invalidated and when the cause why the destination information cannot be acquired is that no destination information corresponding to the ID is stored by the external apparatus, the registered transfer setting is invalidated.