Common law marriage—also known as marriage without formalities or informal marriage—is marriage without a wedding or marriage ceremony and without a marriage license. Some states recognize common law marriage under certain circumstances—such as when the parties agree to be married, live together (cohabit) after agreeing to be married, and represent to others that they are married (holding themselves out as a married couple).

Other states previously recognized common law marriages, but no longer recognize such marriages after a certain date on which the law was changed—usually by statute. In other states, common law marriage has not been recognized by the legislature in a statute, but the courts have recognized common law marriage in court opinions or case law.

In Utah, common law marriage is not recognized in the same way as a traditional marriage that requires a ceremony and a marriage license. However, Utah does provide a mechanism for relationships that resemble a common-law marriage to be legally recognized. Under Utah Code Section 30-1-4.5, a court may formalize a relationship as a marriage if the couple is of legal age and capable of giving consent, have lived together, have treated each other as though they are married, and have presented themselves to the public as husband and wife. This recognition is not automatic and requires a petition to the court. The petition must be filed during the relationship or within one year after the relationship ends (either through separation or death). If the court finds that a marriage has arisen out of a cohabitation relationship, it can issue an order that the relationship is a marriage. It is important to note that this is not the same as a common law marriage being recognized from the outset; rather, it is a legal process to recognize a marriage-like relationship after the fact.