Security deposit limits, eviction notices, rent control, and more for Seattle, Washington.
Every rule on this page is drawn from state statutes and municipal codes and summarized with AI assistance. Each one cites the statute it's based on and links to a published text of that law so you can read it firsthand. Where a page says a city or county has no local rule on a topic, that means none was found for the topics covered here — not that none exists. Local governments also regulate rental housing in ways these pages don't track, including registration, licensing, inspections and habitability standards. These summaries may be incomplete or out of date, laws change often, and every property and tenancy has specifics a summary can't capture — so treat this as a starting point for your own research, not as legal advice, and check with the local jurisdiction and a qualified attorney before acting on your particular situation.
Sources last checked August 2026
Seattle has some of the strongest tenant protections in the United States. Key Seattle-specific protections include: just-cause eviction requirements (SMC 22.206.160) with 16 approved reasons, 180 days' written notice before any rent increase, security deposit capped at 1 month's rent for unfurnished units, first-in-time tenant selection rules, and economic displacement relocation assistance for large rent increases. Washington state's HB 1217 (May 2025) added a statewide rent cap of 7% + CPI or 10%, whichever is less, and requires 90 days' notice for rent increases.
If last month's rent is charged, the written rental agreement must identify the amount and describe the installment-payment terms if the tenant elects installments.
When a landlord takes adverse action based on permissible registry information, the landlord must provide written notice and identify the specific registry information relied upon. The notice may be delivered by email, mail, or in person.
Residential rental agreements and renewals entered into after November 8, 2021 must include, or are deemed to include, a provision requiring prior written notice before periodic or monthly housing costs increase. The standard notice period is 180 days; subsidized tenancies receive a 30-day notice period.
For a housing-cost increase notice that triggers Economic Displacement Relocation Assistance, the owner must provide the notice to an adult tenant by personal delivery or by certified mail, return receipt requested, and first-class mail addressed to the housing unit. The City EDRA notice must be attached.
The security deposit plus nonrefundable move-in fees may not exceed the tenant's first full month of rent. If rent is not paid monthly, the limit is calculated using equal monthly proration.
These state-level rules apply in Seattle where no local override exists.
Under RCW 59.18.650, Washington requires just cause to evict a tenant, refuse to continue a tenancy, or end a periodic tenancy. Permitted grounds include nonpayment of rent (14-day notice to pay or vacate), material lease violations (10-day notice to cure or vacate), substantial property damage, maintaining a nuisance, criminal activity on the premises, and others enumerated in RCW 59.18.650(2). Landlords must provide at least 14 days' written notice before filing an eviction for nonpayment; the notice must include a statement of the tenant's right to pay and cure. At the end of a fixed-term lease, landlords must provide written notice at least 20 days before the end of the lease period if they do not intend to renew. No-cause eviction of month-to-month tenants is prohibited.
Washington limits annual rent increases statewide. Under HB 1217 a landlord may not raise the rent at all during the first 12 months of a tenancy, and after that the increase in any 12-month period is capped at the lesser of 7% plus the June year-over-year change in the Seattle-area Consumer Price Index, or 10%. The Department of Commerce calculates and publishes the resulting figure each year. For calendar year 2026 the maximum allowable rent increase is 9.683%. For calendar year 2027 Commerce published a maximum of 10%, announced on July 15, 2026 — in that year the CPI calculation came out above the statutory ceiling, so the flat 10% cap applies rather than the formula. The two years differ for that reason, not because either is a rounding of the other, and 10% should not be treated as a permanent ceiling: in a year where 7% plus CPI lands below it, the lower number governs. Manufactured and mobile home lots fall under a separate act (RCW 59.20) with a flat 5% cap that is not CPI-indexed and requires 90 days' written notice. Tenancies in a dwelling whose first certificate of occupancy was issued 12 or fewer years before the notice are exempt, measured from the original certificate — a later renovation does not restart that clock.
For month-to-month or other periodic tenancies, RCW 59.18.200 requires either the landlord or tenant to provide at least 20 days' written notice preceding the end of the rental period to terminate the tenancy. The notice must be delivered before the last 20 days of the rental period — the day of delivery does not count toward the 20 days. For fixed-term leases, the lease end date serves as termination; the landlord must provide at least 20 days' written notice of non-renewal if they do not intend to continue the tenancy. Under HB 1217 (2025), landlords must also provide at least 90 days' written notice before the end of a lease term if the reason for non-renewal is for purposes that would otherwise constitute a rent increase or material change in tenancy terms.
Trenly tracks the notices, deadlines, and rule changes behind these laws — so you don't have to watch every statute yourself.
