Washington state has no garage sale permit law. Seattle does not require a permit and follows a 3/yr informal guideline. Bellevue, Redmond, and other King County cities have their own rules — most are no-permit.
Washington Garage Sale Rules — City Detail
Seattle: no permit, ~3/yr guideline. Bellevue: check with city. Tacoma: no permit. Spokane: no permit. Most Washington cities do not require garage sale permits.
Covered Cities in Washington
General Washington Sign Rules
Regardless of whether your city requires a permit, all Washington municipalities follow the general principle that garage sale signs must be posted on private property only. Signs on telephone poles, utility poles, traffic signs, or any public right-of-way are prohibited statewide under various anti-litter and sign codes. Signs should come down promptly after the last day of your sale.
HOA Rules in Washington
City and county permit rules are only part of the picture. In Washington, many residential developments are governed by Homeowners Associations with their own rules about garage sales — sometimes stricter than municipal ordinances. Common HOA restrictions include: advance notice requirements, limits on the number of sales per year (sometimes lower than city limits), designated community sale weekends, sign size and placement rules, and restrictions on certain categories of merchandise. Always check your HOA's CC&Rs before scheduling a sale.
No — Washington has no statewide garage sale permit law. All permit requirements are set at the city, county, or township level. Rules vary enormously from one municipality to the next.
Most states, including Washington, have an "occasional sale" or "casual sale" exemption that excludes one-time or infrequent sales of used personal household property from sales tax. If you're selling regularly or selling new merchandise, consult your state's department of revenue or a tax professional.
The rules of the city or county within whose jurisdiction your address falls are what apply — not the rules of the nearest city. Check your property tax bill, utility bill, or the county GIS portal to confirm your legal jurisdiction. When in doubt, call both municipalities.