Some states have statutes that provide that if parties have resided together, even though they were not formally married, they will be treated as if they were actually married. Washington State does not have a common law marriage statute.

In the absence of any statutory authority, the courts have provided that assets and debts may be divided as if they were married under a theory called a “committed intimate relationship” (CIR).

The Washington State Supreme Court has clarified the requirements. In Re Pennington, 142 Wn.2d 592 (2000). A committed intimate relationship is a stable relationship evidenced by such nonexclusive factors as cohabitation, duration, purpose, pooled resources, mutual services, and intent of the parties. Distribution of property acquired during a committed intimate relationship is subject to a three-part test: (1) the trial court must determine whether a committed intimate relationship exists; (2) if such a relationship exists, the trial court evaluates the interest each party has in the property acquired during the relationship; (3) the trial court then makes a just and equitable distribution of such property.

A CIR does differ from a divorce in significant ways, however:

The separate property of one partner may not be awarded to the other partner of a CIR. Estate of Langeland, 195 Wn. App. 74, 85, __ P.3d __ (2016).

Attorney fees cannot be awarded in a CIR because RCW 26.09.140 is restricted to marriages. Foster v. Thilges, 61 Wn. App. 880, 887, 812 P.2d 523 (1991).

Maintenance (alimony) cannot be ordered in the absence of a lawful marriage. Lloyd v. Superior Court of King County, 55 Wash. 347, 104 P. 771 (1909).