Wash. Rev. Code § 30A.20.090
Notice to any national bank, state bank, savings bank, or bank under the supervision of the director, doing business in this state of an adverse claim to a deposit standing on its books to the credit of any person may be disregarded without liability by said bank unless said adverse claimant shall also either procure a restraining order, injunction or other appropriate process against said bank from a court of competent jurisdiction in a cause therein instituted by him or her wherein the person to whose credit the deposit stands is made a party and served with summons or shall execute to said bank, in form and with sureties acceptable to it, a bond, in an amount which is double either the amount of said deposit or said adverse claim, whichever is the lesser, indemnifying said bank from any and all liability, loss, damage, costs and expenses, for and on account of the payment of such adverse claim or the dishonor of the check or other order of the person to whose credit the deposit stands on the books of said bank: PROVIDED, That where the person to whose credit the deposit stands is a fiduciary for such adverse claimant, and the facts constituting such relationship, and also the facts showing reasonable cause of belief on the part of said claimant that the said fiduciary is about to misappropriate said deposit, are made to appear by the affidavit of such claimant, the bank shall without liability refuse to deliver such property for a period of not more than five business days from the date that the bank received the adverse claimant's affidavit, without liability for the sufficiency or truth of the facts alleged in the affidavit, after which time the claim shall be treated as any other claim under this section.
This section shall not apply to accounts subject to chapter 30A.22 RCW.
RCW 30A.20.090
Effective date-1981 c 192: See RCW 30A.22.900.