Under current Washington law for month-to-month tenancies either the landlord or tenant can end the tenancy with written notice given the last day of the rental period (usually but not always the last day of a calendar month) served at least 20 days in advance.
In Seattle residential landlords must have just cause to evict, even if the tenant is month-to-month. Without just cause, the landlord has a perpetual tenant. A Seattle residential tenant meanwhile can still terminate the tenancy on 20 days notice.
If a lease provision calls for more than 20 days, the parties must give the longer notice required by the lease terms.
A recent bill in the legislature would extend the notice period if the tenant has occupied the property for two years or more. If the tenant has occupied the property for two or more years the proposed new law would require either party to give 60 days notice to terminate the month-to-month tenancy.
The bill was proposed in 2016 and never came out of committee. If the bill ever becomes law we will of course update our website and forms.
