Wash. Rev. Code § 81.08.030
A public service company may issue stock and stock certificates or other evidence of interest or ownership, or bonds, notes or other evidence of indebtedness payable on demand or at periods of more than twelve months after the date thereof, for the following purposes only: The acquisition of property, or the construction, completion, extension, or improvement of its facilities, or the improvement or maintenance of its service, or the issuance of stock dividends, or the discharge or refunding of its obligations, or the reimbursement of moneys actually expended from income or from any other moneys in the treasury of the company not secured by or obtained from the issue of stock or stock certificates or other evidence of interest or ownership, or bonds, notes or other evidence of indebtedness of the company for any of the aforesaid purposes except maintenance of service, in cases where the applicant keeps its accounts and vouchers for such expenditures in such manner as to enable the commission to ascertain the amount of money so expended and the purpose for which the expenditure was made.
RCW 81.08.030