Wash. Rev. Code § 84.25.100
The governing authority may establish an application fee. This fee may not exceed an amount determined to be required to cover the cost to be incurred by the governing authority and the assessor in administering this chapter. The application fee must be paid at the time the application for limited exemption is filed. If the application is approved, the governing authority of the city must pay the application fee to the county assessor for deposit in the county current expense fund, after first deducting that portion of the fee attributable to its own administrative costs in processing the application. If the application is denied, the city's governing authority may retain that portion of the application fee attributable to its own administrative costs and refund the balance to the applicant.
RCW 84.25.100