Cities that impose a general business license must adopt the mandatory provisions of the model ordinance as provided in RCW 35.90.080 by January 1, 2019. A city that has not complied with the requirements of this section by January 1, 2019, may not enforce its general business licensing requirements on any person until the date that the mandatory provisions of the model ordinance take effect within the city.
RCW 35.90.090