Numa typically answers calls through a standard phone feature available on most plans and most carriers: Call Forwarding
Call Forwarding directs an incoming callers phone call from one destination (your business) to another destination (Numa).
For most businesses Numa recommends that you configure your phones to forward missed calls to Numa (so you have the option to answer them first). This is commonly referred to as Conditional Call Forwarding. More specifically:
Call Forwarding No Answer - Forwards unanswered calls to Numa after a set amount of rings (some phone providers allow you to adjust the number or rings before a call is forwarded)
Call Forwarding Busy - Forwards calls to Numa when the phone line is busy.
If you don't answer your business phone (or don't want to anymore) you can send all phone calls to Numa.
Call Forwarding Always - Immediately forwards all calls to Numa
For your convenience we have compiled a list of articles describing how to do this for most phone providers.