Marriage in Washington (1998)

26.04.010 Marriage contract—Void marriages. (1) Marriage is a civil contract between a male and a female who have each attained the age of eighteen years, and who are otherwise capable.

(2) Every marriage entered into in which either the husband or the wife has not attained the age of seventeen years is void except where this section has been waived by a superior court judge of the county in which one of the parties resides on a showing of necessity. 

26.04.020 Prohibited marriages. (1) Marriages in the following cases are prohibited:

     (a) When either party thereto has a wife or husband living at the time of such marriage;

     (b) When the husband and wife are nearer of kin to each other than second cousins, whether of the whole or half blood computing by the rules of the civil law; or

     (c) When the parties are persons other than a male and a female. 

(2) It is unlawful for any man to marry his father's sister, mother's sister, daughter, sister, son's daughter, daughter's daughter, brother's daughter or sister's daughter; it is unlawful for any woman to marry her father's brother, mother's brother, son, brother, son's son, daughter's son, brother's son or sister's son. 

(3) A marriage between two persons that is recognized as valid in another jurisdiction is valid in this state only if the marriage is not prohibited or made unlawful under subsection (1)(a), (1)(c), or (2) of this section.