In order to have a valid common law marriage, the couple must do all of the following:

- Live together for a significant period of time (not defined in any state).

- Hold themselves out as a married couple. Typically this means using the same last name, referring to  the other as "husband" or "wife," and filing a joint tax return.

- Intend to be married.

When a common law marriage exists, the spouses receive the same legal treatment that is given to formally married couples. This also includes the requirement that they go through a legal divorce to end the marriage.