• Common-law marriage is unusual in the United States.marriage defined image by Christopher Walker from Fotolia.com
  
  In most U.S. states, legal marriages require state-issued marriage licenses. In a few states, however, "common law" marriages are recognized. In a common-law marriage, a couple lives together for a "significant" period of time; acts as a married couple, including sharing a last name, referring to one another as husband and wife, and filing joint tax returns; and "intend" to be married. Spouses in common-law marriages are legally recognized, including requiring a court order to end the relationship. A common-law marriage effective in a state where they are legal must be recognized in states where they are not. Some states have specifically outlawed common-law marriages.
  
  

Alabama

• In Alabama, legally establishing a common-law marriage requires: capacity (ability to enter into a marriage); agreement to be husband and wife; public recognition of the union; and sexual consummation of the marital relationship.
  
  

Colorado

• In Colorado, legal recognition of common-law marriages requires: legal ability to be married, consent, proof of cohabitation and an exclusive relationship; and a "reputation"--public acknowledgement--of marriage.
  
  

Kansas

• In Kansas, to enact a common-law marriage, a man and woman must both be at least 18, possess the mental capacity for marriage, mutual agree to the union, and have a public reputation of being married.
  
  

Rhode Island

• For a common-law marriage to be valid in Rhode Island, the man and woman must seriously intend to be married and conduct themselves so their community reasonably believes they are married.
  
  

South Carolina

• For a legal common-law marriage in South Carolina, a man and a woman must demonstrate publicly their intention to be married. A common-law marriage is established if a man and woman mutually agree to the marriage and intend for others to believe they are married.
  
  

Iowa

• In Iowa, the three elements necessary to establish a common-law marriage are: "intent and agreement," continuous cohabitation, and public declaration of the marriage. The "acid test" of common-law marriages in Iowa is considered the public declaration or community belief in the marriage.
  
  

Montana

• To establish a common-law marriage in Montana, there must be the ability to enter into a marriage, a mutual agreement to the marriage, living together as a couple, and a reputation within the community of being married.
  
  

Oklahoma

• In Oklahoma, the man and woman entering into a common-law marriage must both be competent and able to be married. They must also mutually agree to the marriage relationship and cohabit with one another.
  
  

Texas

• While Texas recognizes common-law marriage, to be legalized the couple must still sign a form available from the county clerk. They must also agree to the marriage, live together, and publicly represent their marriage to the community.
  
  

District of Columbia

• The District of Columbia has two requirements for common-law marriages. Those participating must exhibit an express intent to be married, and cohabit.
  
  

Miscellaneous

• In addition to the states listed, five others--Georgia, Idaho, Ohio, Oklahoma, and Pennsylvania--have "grandfathered" common law marriage into their legal system. This means common-law marriages affected before certain dates will continue to be legally recognized. New Hampshire also recognizes common-law marriage, but only for inheritance purposes, and Utah recognizes common-law marriages validated by court order.