The Phone app's Voicemail menu will let you record a custom greeting that you can edit at any time. If you want to check that you set up your voicemail correctly, call your iPhone using another phone.
When asked to press a number, pause on the phone/mic icon and click a number under the DIAL PAD tab.

While missed calls aren’t ideal, you can let your caller know you’re still there for them by having a great voicemail greeting. The best business voicemail greetings let your customers (and potential customers) know why you’re not available and how they can best get in contact with your business. They are also short and to the point. You usually want to keep your greeting between 6 and 24 seconds long so callers don’t hang up halfway through.
There are a lot of benefits to having a professional voicemail greetings. Also take a look at our pre recorded voicemail greeting - starting at $ 29. With us we will allow you to pick a voice talent that would best suit the image of your business company. In accordance with your company phone system, the recordings will be delivered in any file format you need. It is that easy.