Depending on what cellular provider you have and where in the world you are, the process may differ a little bit. Searches can likely be made to find the specific instructions for your specific provider. All in all, however, most of the set-ups are fairly similar and shouldn’t take very long at all. So without further ado, let’s take a look at the ways to set up your voicemail on the iPhone 6S.
Some iPhone owners are reporting issues with their voicemail after updating to iOS 11 or later. Instead of being able to listen to a voicemail directly on their iPhone, the Voicemail section of the Phone app instead prompts users to "Call Voicemail." An Apple support document suggests resetting your Networks Setting to return to Visual Voicemail. You can do this by navigating to Settings > General > Reset. Now tap "Reset Network Settings" and enter your passcode. Your phone will then reboot.

With Visual Voicemail, you can see a list of your messages and choose which ones to listen to or delete. Learn how to set up and transfer your existing voicemail. Create a voicemail password, then tap Done. Enter your password again to confirm it, then tap Done. Select Custom or Default. If you choose Custom, you can record a new greeting. Go to the Phone app, then tap the Voicemail tab. Tap Set Up Now. Enter your password,* then tap done. Record a custom greeting or use the default greeting, then tap Save.
Hi! John’s answering machine is broken. This is his refrigerator. Please speak very slowly, and I’ll stick your message to myself with one of these magnets.