Yes, you still need to do business with the prison phone company - their role is to monitor all of the calls and they have a monopoly arrangement to do so. Instead of registering your old "long distance number" and paying $15-18 per call, you register the new "Local number" and Global Tel can only charge the local line fee - approximately $1.75 per call.
https://www.inmateaid.com/ask-the-inmate/if-i-get-a-discounted-telephone-do-i-still-have-to-buy-prepay-phone-cards-from-gtl#answer
Accepted Answer Date Created: October 26,2013