You will need to obtain a Marriage License from the county recorder's office. For incarcerated persons, they will not be in a position to appear before the county recorder to apply with you for the marriage license. Instead, the inmate will need to sign a form called “Affidavit of Inability to Appear." This Inability to Appear form must be notarized. There are costs associated with these functions, we do not know what they are.
https://www.inmateaid.com/ask-the-inmate/does-it-cost-anything-to-marry-an-inmate#answer
Accepted Answer Date Created: May 16,2016