Apple repairs iPhones at the Genius Bar in Apple Stores and through their online mail-in repair service. Apple repairs are high-quality, but out-of-warranty repairs can be much more expensive than third-party solutions. If you're looking to save some money you're not covered by Apple's warranty, you may want to check out our other recommendations.
Navigate to your Phone app located at the bottom of your iPhone home screen. Tap-open the Phone app. Once you have done that, you will see a voicemail logo the bottom right corner of the window that has opened, select that voicemail icon. That action will open the visual voicemail interface. At first, all you will see is a blank screen with a

From 1 October 2016 the Apple Visual Voicemail feature will be activated by default for all Truphone customers with an iPhone running on iOS 8.1 or above.
Jan 21, 2008 · Where "(your phone number)" is your 11-digit phone number (including 1 and the area code), and "15" is the number of seconds (from 5 to 30 in 5 second increments) that you want your phone to ring before going to voicemail. (The default seems to be 10 seconds.) You can thank me later. 😉 (Hat tip to Bradley!)