The first thing that you need to do is to switch on your iPhone and unlock the home-screen by slide your finger on the bottom of the screen. Make sure that the battery is not running too low as you do not want the phone to die halfway through the process.
Next, you need to find out the number of your voice inbox. In order to do this, tap the phone icon located on the bottom of the home-screen and use the keypad that appears on the screen to type “#61#” without the quotes. Press the “Call” button highlighted in green.
Note down the number that the service gives you on a piece of paper on a Word document on your computer.
Return back to the home-screen of your iPhone and locate the icon for “Settings.” Tap the icon to open it.
Scroll down until you see “Phone” and then tap it to open it up.
In the menu under the “Calls” section, locate and tap “Call Forwarding” to access the menu that allows you to turn it off or on.
Tap the button in front of “Call Forwarding” to switch it on. Your phone will ask you to enter the number to which you want to forward the calls. Remember the number that you received from the service in the third step. You need to enter that number here. Refer to the piece of paper or Word document where you wrote that number to ensure that you do not end up entering a different number.
Next, you will need to disable the voice mail. To do this, return to the home-screen of your iPhone, locate the phone icon on the bottom of the screen and tap it. Press the keyboard icon located on the bottom of the screen that appears to a keyboard appear on the screen.
Type “#004#” without the quotes and tap the “Call” button. This will successfully deactivate your voice mail service.