An image processing apparatus and control method are provided. The image processing apparatus includes: a communication interface which is configured to communicably connect to a server; a voice input interface which is configured to receive a speech of a user and generate a voice signal corresponding the speech; a storage which is configured to store at least one user account of the image processing apparatus and signal characteristic information of a voice signal that is designated corresponding to the user account; and a controller which is configured to, in response to an occurrence of a log-in event with respect to the user account, determine a signal characteristic of the voice signal corresponding the speech received by the voice input interface, select and automatically log in to a user account corresponding to the determined signal characteristic from among the at least one user account stored in the storage, and control the communication interface to connect to the server with the selected user account.