You can set up voicemail on your Android phone directly from the phone's keypad or its Voicemail app if it features one.
Open the Phone app. Tap the menu button at the top and choose Settings from the list of options. Scroll down and select ...
You can set up voicemail on your iPhone through the Phone app, which will let you record a custom greeting that you can edit at any time.
Most people that buy a modern Android phone expect it to work out of the box with minor tinkering. That's also true of various phone features, like reliable connectivity, performance, and storage. But ...