Wash. Rev. Code § 25.10.351
(1) Except as otherwise provided in subsection (2) of this section, a person that makes an investment in a business enterprise, and erroneously but in good faith believes that the person has become a limited partner in the enterprise, is not a general partner and is not liable for the enterprise's obligations by reason of making the investment, receiving distributions from the enterprise, or exercising any rights of or appropriate to a limited partner, if, on ascertaining the mistake, the person:
[ 2009 c 188 s 306.]