If you do not have a contact that matches the number that called, Infusionsoft will add that number to a new contact with no name attached to it, and will apply the tag. This will allow you to sort based on your tag to be able to followup with them.
EXAMPLE USE CASE:
You can have your Twillo number forward to a conference call line by using the conference call number as the redirect number and by removing the voice message. This way, you can tag people who join your conference call. NOTE: The length of the conference call will be charged to your Twillio account, BUT you’ll be able to followup with people who took action if the purpose was to gain potential leads.