This affidavit is used. To make complete disclosure of income, expenses, and money owed.An affidavit of marriage is a legally binding document that proves a legal marriage exists between two people. An affidavit is a written statement made under oath that is typically used in legal proceedings. Learn their purpose, when to use, and how to write. The Franklin County Probate Court issues marriage licenses to residents of Franklin County, Ohio who are planning to marry in the state of Ohio. An affidavit is a written declaration under oath, made without notice to the adverse party. Marriage laws vary from state to state. An affidavit is a sworn statement of fact that can be used in a variety of legal proceedings, from bankruptcy cases to family and civil litigation matters. A written statement that someone makes after promising officially to tell the truth.