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 Kansas, common law marriage is recognized under certain conditions. For a common law marriage to be valid, the couple must have the capacity to marry, must agree that they are married, must live together as a couple, and must represent to others that they are married. This is often referred to as 'holding out' to the public as a married couple. There is no specific time requirement for how long a couple must live together to establish a common law marriage. It is important to note that if a common law marriage is established in Kansas, it is recognized as a legal marriage with all the rights and responsibilities that come with a ceremonial marriage. This includes the requirement to go through a formal divorce process to end the marriage. It's also worth mentioning that if a couple has a valid common law marriage in Kansas and moves to another state that does not recognize common law marriage, the Full Faith and Credit Clause of the U.S. Constitution requires the new state to recognize the marriage.