Common Law Marriages
A common law marriage is a marriage by agreement of the two persons without any formal ceremony or license. A common law marriage will be recognized in Kansas if the couple considers themselves to be married and publicly holds themselves out to be married and if they are legally eligible to marry. No minimum period of cohabitation is required.
Common Law marriages are subject to the same legal obligations and privileges that apply to marriages with licenses. Once a common law marriage is established, the couple must get a court ordered divorce to terminate the marriage.
https://www.ksbar.org/page/marriage_divorce
Common law marriage in Kansas