Wash. Rev. Code § 42.16.014
Disbursements from the revolving account and fund created by RCW 42.16.010 through 42.16.017 shall be by warrant in accordance with the provisions of RCW 43.88.160: PROVIDED, That when the payroll is prepared under a centralized system established pursuant to regulations of the director of financial management, disbursements on behalf of the agency shall be certified by the head of the agency preparing the centralized payroll or his or her designee: PROVIDED FURTHER, That disbursements from a centralized paying agency representing amounts withheld, and/or contributions, for payment to any individual payee on behalf of several agencies, may be by single warrant representing the aggregate amounts payable by all such agencies to such payee. The procedure for disbursement and certification of these aggregate amounts shall be established by the director of financial management.
All payments to employees or other payees, from the revolving account and fund created by RCW 42.16.010 through 42.16.017, whether certified by an agency or by the director of financial management on behalf of such agency, shall be made wherever possible by a single warrant reflecting on its face the amount charged to each revolving account and fund.
RCW 42.16.014