Seattle Security Deposit Rules: What the Rental Agreement Regulation Ordinance Adds to Washington Law

A landlord in Seattle has to satisfy two sets of rules at once: the Washington statute, Wash. Rev. Code § 59.18.280, and the city's own Rental Agreement Regulation Ordinance (SMC ch. 7.24). The state law sets the 30-day return deadline after termination of the tenancy and the tenant vacating; the local ordinance adds rules on deposit cap, paying the deposit in installments, return deadline and rent-increase notice. Where the two overlap, the landlord has to meet the stricter one.

What the Rental Agreement Regulation Ordinance adds

• Deposit cap: Security deposit plus non-refundable move-in fees together may not exceed one month's rent; move-in fees alone are capped at 10 percent of first month's rent and pet deposits at 25 percent. (SMC 7.24 (section number not verified from code text))
• Paying the deposit in installments: Tenants may pay deposits and move-in fees in installments: six monthly installments for leases of six months or more, four for 30 days to six months, two for month-to-month, and pet deposits in three; no fee or interest may be charged for installments. (SMC 7.24 (section number not verified from code text))
• Return deadline: The landlord must return the deposit and/or a full statement of any withheld portion within 30 days of move-out, and must refund the full deposit if no signed move-in checklist exists. (SMC 7.24 (section number not verified from code text))
• Rent-increase notice: Seattle requires at least 180 days' written notice before any increase in a renter's housing costs. (SMC 7.24 (section number not verified from code text))

Who it covers: Residential tenancies in Seattle regulated by SMC 7.24; official pages do not list exemptions beyond those in state law.
Worth knowing: The rules above come from three official Seattle Department of Construction and Inspections pages that each cite SMC Chapter 7.24; the exact section numbers were not confirmed from the code text for this article. Seattle also requires 180 days' written notice before any increase in housing costs.

What Washington law already requires

• Return deadline: 30 days after termination of the tenancy and the tenant vacating.
• Detail: Changed from 21 to 30 days in 2023 (HB 1074). Deductions must be documented with invoices or estimates, and no wear-and-tear deductions are allowed without a signed move-in checklist.
• Itemized deductions: required in writing.
• Forwarding address: not a statutory condition of getting the deposit back.
• Penalty for wrongful withholding: Intentional refusal to return or itemize exposes the landlord to up to twice the deposit plus attorney's fees; missing the deadline forfeits the right to withhold.
• Small claims limit: $10,000.
• Statute: Wash. Rev. Code § 59.18.280.

Using both rules together

1. Read the lease for the deposit amount, the move-in date, and any clause that mentions the ordinance.
2. Check the local rule first: deposit cap under SMC ch. 7.24, then paying the deposit in installments, return deadline and rent-increase notice.
3. Count the Washington deadline of 30 days from termination of the tenancy and the tenant vacating.
4. A written demand that cites both Wash. Rev. Code § 59.18.280 and SMC ch. 7.24 carries more weight than one that cites either alone. Intentional refusal to return or itemize exposes the landlord to up to twice the deposit plus attorney's fees; missing the deadline forfeits the right to withhold.

Frequently Asked Questions

Q: Does Seattle require interest on security deposits?
A: The Rental Agreement Regulation Ordinance does not add an interest rule, so Washington law governs. Wash. Rev. Code § 59.18.280 does not require interest on deposits.

Q: Is the Seattle deposit return deadline different from Washington law?
A: Yes. The landlord must return the deposit and/or a full statement of any withheld portion within 30 days of move-out, and must refund the full deposit if no signed move-in checklist exists. Where the local rule is stricter than Wash. Rev. Code § 59.18.280, the stricter one is the one a landlord has to meet.

Q: Does the Rental Agreement Regulation Ordinance apply to my unit?
A: Residential tenancies in Seattle regulated by SMC 7.24; official pages do not list exemptions beyond those in state law. Check the section cited below for the full list of exemptions before relying on it.

Q: Can I sue my landlord in small claims court for my Washington deposit?
A: Yes. Washington small claims court hears claims up to $10,000, which covers most deposits plus the statutory penalty. A dated written demand that cites Wash. Rev. Code § 59.18.280 is the usual first exhibit.

Sources Checked

• SMC 7.24, Rental Agreement Regulation Ordinance: official page, read 2026-09-20
• Wash. Rev. Code § 59.18.280 (the Washington statute cited above)
• LeaseLenses Washington deposit data set, last reviewed 2026-09-19; the same data powers the Washington demand letter tool
• Washington landlord-tenant overview and the Washington deposit rules page

This page is general legal information for Seattle, Washington, not legal advice. Local ordinances are amended more often than state statutes; read the current code text before relying on a figure in court.