One of the services we tried for the Infinite-Range Wireless Intercom
was a 3G AT&T GoPhone which we purchased from WalMart for $19.99. It includes a telephone you can use to set
the service up and test (Make sure you choose a 3G phone and NOT a 4G). The
has website that lets you
add minutes in the future if you choose that type of a plan. You'll notice that on the lower end plans the text messaging is very expensive. While you are programming your intercom, we recommend you do a Google search for "Free Text Messaging" and use one of the tools you find to program the system so you don't use expensive text messaging.
The following video walks you through the process of setting up the AT&T
GoPhone service once you buy the phone.