There are a lot of towns in South Dakota where you are unable to port your local phone numbers to different carriers. This makes it difficult to use a hosted phone system from a company different from the local carrier. Here’s a workaround: port your number(s) to Verizon OneTalk. Due to cellphone service, the chances of porting to Verizon are pretty good. Pay for a single OneTalk service per number and put a call-forward-always to the number of your new hosted phone service. That number will be “long distance” because they’re only available in Pierre, Rapid City, or Sioux Falls. BUT because your number has ported to Verizon, and Verizon is unlimited and no “long distance,” you won’t incur long distance charges.
Assign your phones with the caller ID number of your main line so all outbound calls identify as your company number.