Many businesses use 0800 numbers as free phone access for their customers.  However, this is not free to your company.  VoIP allows you to have unlimited numbers with each routing to the same location.  You can also choose your own area code.  You might be in Wellington or Christchurch but you can have an 09 area code.  When you move to a new location, your number and area code doesn’t have to change.  Your phone number, like your email address, is a virtual one and now connects to a location in cyberspace.