Depending on the facility, it could be immediate or it might be several days. If your inmate has to go through Admissions & Orientation, there will be a short delay before the privileges are set up and working for your inmate.
https://www.inmateaid.com/ask-the-inmate/how-soon-after-an-inmate-is-booked-in-can-they-use-the-phone-service#answer
Accepted Answer Date Created: March 12,2015