Notice before a rent increase
Give at least 90 days' prior written notice of any rent increase on the state form, and the increase cannot take effect before the lease term ends (RCW 59.18.140(3); RCW 59.18.720).
30 days for subsidized tenancies where rent is based on tenant income. Notice must use the statutory 'Rent and Fee Increase Notice' form (RCW 59.18.720) and cannot take effect before the end of a fixed term. Local: Seattle 180 days; Tacoma and Bellingham 120 days.
RCW 59.18.140(3), RCW 59.18.720 · checked October 26, 2026
Rent control
Landlords may not raise rent during the first 12 months of a tenancy or by more than 7% plus CPI or 10% (whichever is less; 9.683% for 2026 and 10% for 2027 per Commerce) in any 12-month period unless an exemption such as a building under 12 years old applies, and cities are barred from adopting their own rent control (RCW 59.18.700-.710; RCW 35.21.830).
RCW 59.18.700, RCW 59.18.710, RCW 35.21.830 · checked October 26, 2026
Notice to end a month-to-month tenancy
A landlord cannot end a month-to-month tenancy without one of the just causes listed in RCW 59.18.650, and the notice depends on the cause (for example 90 days for owner move-in or sale of a single-family home, 120 days for demolition or conversion), while a tenant may end it with 20 days' written notice before the end of a rental period (RCW 59.18.650; RCW 59.18.200(1)).
Just cause required: a landlord cannot end a month-to-month tenancy just by giving notice. Notice depends on the cause: 14 days (nonpayment), 10 days (cure lease violation), 3 days (waste/nuisance/unlawful activity), 20 days (owner-shared unit; sexual harassment), 30 days (condemned unit; application fraud; end of transitional housing program), 60 days (legitimate business/economic reason; 4+ violations in 12 months; sex-offender registration; no-cause end of an initial 6-12 month lease that would otherwise roll to month-to-month), 90 days (owner/family move-in; sale of single-family home), 120 days (demolition, substantial rehab, change of use, condo conversion). Tenant: 20 days before end of rental period.
RCW 59.18.650, RCW 59.18.200, RCW 59.12.030(2) · checked October 26, 2026
With 90 days' notice delivered on November 1, 2026, the earliest effective date the form accepts is January 30, 2027, and the example moves it to the first day of a month on or after that date. Washington's rule above sets different terms in some situations, so set the form's notice period to the one that fits your tenancy.
City and county rules can be stricter than state law, and your lease can require more than the statute does. Use whichever rule gives the tenant more time or protection.