Wash. Rev. Code § 43.09.280
The expense of auditing public accounts shall be borne by each entity subject to such audit for the auditing of all accounts under its jurisdiction and the state auditor shall certify the expense of such audit to the fiscal or warrant-issuing officer of such entity, who shall immediately make payment to the state auditor. If the expense as certified is not paid by any local government within thirty days from the date of certification, the state auditor may certify the expense to the auditor of the county in which the local government is situated, who shall promptly issue his or her warrant on the county treasurer payable out of the current expense fund of the county, which fund, except as to auditing the financial affairs and making inspection and examination of the county, shall be reimbursed by the county auditor or chief financial officer designated in a charter county out of the money due the local government at the next monthly settlement of the collection of taxes and shall be transferred to the current expense fund.
RCW 43.09.280