Once the number has been added to the approved call list, the timeline depends on where the inmate is in the facility's intake and orientation process.
For someone who has already completed orientation at Northern State Prison, the number can be active and available for calls within a few days of being submitted. The phone carrier has to process the new number and add it to the approved list in their system, and that typically takes two to four business days once the request is submitted correctly.
For someone who has just arrived at the facility, the orientation process has to come first. Most facilities do not allow new arrivals full phone access until they have cleared intake, been medically screened, received their housing assignment, and completed the orientation program. That process generally takes up to a week from arrival before phone privileges are fully active. Once orientation is complete and the number is on the approved list, calls can begin.
The practical advice is to get the InmateAid number to your inmate as early as possible so they can submit it during or immediately after orientation rather than having to do it as a separate step later. Sending the number in a letter through InmateAid or by mail right away means it is in his hands when he needs it.
If a week has passed since he added the number and calls are still not coming through, have him check with the unit officer to confirm the number was processed correctly in the system. Occasionally submissions get missed or entered incorrectly and a quick verification resolves it.