Common law marriage is allowed in a minority of states. A common law marriage is a legally recognized marriage between two people who have not purchased a marriage license or had their marriage solemnized by a ceremony. Not all states have statutes addressing common law marriage. In some states case law and public policy determine validity.
States With Common Law Marriage
Colorado: Common law marriage contracted on or after Sept. 1, 2006, is valid if, at the time the marriage was entered into, both parties are 18 years or older, and the marriage is not prohibited by other law (Colo. Stat. §14-2-109.5)
Iowa: Common law marriage for purposes of the Support of Dependents Chapter (Iowa Code §252A.3) Otherwise it is not explicitly prohibited (Iowa Code §595.1A)
Kansas: Common law marriage will be recognized if the parties are 18 or older and for purposes of the Divorce and Maintenance Article, proof of common law marriage is allowed as evidence of marriage of the parties (Kan. Stat. §23-2502; Kan. Stat. §23-2714)
Montana: Not strictly prohibited, they are not invalidated by the Marriage Chapter (Mont. Stat. §40-1-403)
New Hampshire: Common Law Marriage: “Persons cohabitating and acknowledging each other as husband and wife, and generally reputed to be such, for 3 years shall thereafter be deemed to have been legally married, until one of them dies.” (N.H. Stat. §457:39)
South Carolina: allows for marriages without a valid license (S.C. Stat. §20-1-360)
Texas: Common Law Marriage in specific circumstances (Tex. Family Law §1.101; Tex. Family Law §2.401-2.402)
Utah: Utah Stat. §30-1-4.5
Not all state statutes expressly allow for common law marriages. In some states case law recognizes common law marriages, including Alabama and Rhode Island. Oklahoma's statute requires couples to get a marriage license; however case law has upheld common law marriages in the state.