Visual Voicemail is an optional application for the iPhone. In addition to providing a text version of your voice mail, it also enables you to have the Visual Voicemail icon on your iPhone home screen. Although there is no charge for this service, you have to install and activate it before use.
Navigate to the iPhone store from the handset.
Search for the voice mail by typing "AT&T Voicemail Viewer" in the search field. Select either the personal or business voice mail. The summary screen will launch.
Select the "Free" icon. An "Install" icon will replace the "Free" icon.
Select "Install." Your iTunes password may be requested. The voicemail application will begin downloading. Once it is complete, the icon will be displayed as "VM Viewer" on your handset. The number of messages received will be displayed on the "VM Viewer" icon.
Call your number using the handset.
Select the "*" key after you hear the automated operator advising you that voice mail is not activated.
Follow the instructions given by the operator to set up the voice mail.
Reset your iPhone by holding the sleep and home screen keys simultaneously until the handset turns off. After your phone is powered back on, the voice mail will be activated.