An affidavit of marriage is a legal document establishing proof of a legal union between two people. Both parties must be present when this document is executed. It is generally executed before an authorized official. The requirements and restrictions of an affidavit of marriage vary from state to state. The main purpose of an affidavit of marriage is to recognize a marriage as a legal bond. It acts as a state acknowledged proof of the relationship. It is also called as marriage affidavit. An affidavit of marriage can be executed only by those couples who share the same regular permanent residence, have a close relationship, are not married to anyone else, share living expenses, are of a valid marrying age, are not related by blood and mentally competent enough to sign the document.