RCW 35.21.690
RCW 35.21.690: Authority to regulate auctioneers—Limitations.
A city or town shall not license auctioneers that are licensed by the state under chapter 18.11 RCW other than by requiring an auctioneer to obtain a general city or town business license and by subjecting an auctioneer to a city or town business and occupation tax. A city or town shall not require auctioneers that are licensed by the state under chapter 18.11 RCW to obtain bonding in addition to the bonding required by the state.