Yes, you can be charged. This depends on the service. For example, Spectrum’s Voice Residential Services Price Guide charges $3.95 for voicemail.
A professional voicemail greeting is a recorded message that welcomes callers to your business when no one is available to pick up the call. For a polished call experience, the greeting should reflect who the client is calling – whether a general business …

Reassuring the caller that they contacted the correct number or reached the person they intended helps reduce the number of hang-ups and wasted messages you’ll receive. Here are a few notes on how to leave the best greeting possible, along with some voicemail message examples you can use in your own company!
Most VoIP solutions will require stable and consistent internet connectivity at all your office locations where VoIP will be used. At the very least, your business phone system must have access to a business-class internet link, so discuss these needs with your company's internet service provider (ISP). This should be a dedicated link through a dedicated router if you expect your phone calls to sound as if they were coming from a business and not someone's home Skype connection. At a minimum, it's important to have a router that can create virtual LANs (VLANs) and also has the ability to encrypt your voice traffic. These days, you need end-to-end VoIP security for any call.