The most common reason for a sudden block is an accidental tap on your smartphone. Prison systems often use different routing numbers, which your phone might mistake for spam. JustAnswer How to Unblock a Number on an Android Phone - Avast
If you have cleared carrier hurdles and established a prepaid account, but calls still fail, the restriction may be coming from the prison administration. how to unblock a prison call
. Blocks are often accidental or due to security settings and billing limits. 1. Check Your Device Settings The most common reason for a sudden block