An image processing apparatus includes a communicator portion that communicates with a portable terminal apparatus having an address book, a contact data obtaining portion that obtains contacts from the address book, the contacts including contact names and addresses, a registration portion that registers the contacts to a shared address book along with user identification information indicating the log-in user, a display, and a display controller that makes the display show the contacts at least by the contact name, the contacts being registered in the shared address book, that judges whether or not the shared address book contains contacts with different contact names but with identical addresses, and that, if it contains contacts with different contact names but with identical addresses, makes the display show any of the contacts by the contact name, the any contact having the user identification information indicating the log-in user.