RCW 26.60.030: Requirements.

To enter into a state registered domestic partnership the two persons involved must meet the following requirements:

(1) Both persons share a common residence;

(2) Both persons are at least eighteen years of age and at least one of the persons is sixty-two years of age or older;

(3) Neither person is married to someone other than the party to the domestic partnership and neither person is in a state registered domestic partnership with another person;

(4) Both persons are capable of consenting to the domestic partnership; and

(5) Both of the following are true:

(a) The persons are not nearer of kin to each other than second cousins, whether of the whole or half blood computing by the rules of the civil law; and

(b) Neither person is a sibling, child, grandchild, aunt, uncle, niece, or nephew to the other person.