Washington Rent Increase Notices: The Complete 2026 Compliance Guide

Washington Rent Increase Law: What Changed in 2025

Washington's rental landscape underwent its most significant legislative overhaul in decades during 2025. Two landmark bills fundamentally changed how landlords and property managers must handle rent increases:

• HB 1003 (effective July 27, 2025): Requires rent increase notices to be sent via certified mail posted from within Washington State. This eliminated the option of sending notices by regular first-class mail alone.
• HB 1217 (effective July 1, 2025): Introduced Washington's first rent cap, limiting most increases to 7% plus the Consumer Price Index (CPI), with a hard ceiling of 10%.

These changes sit on top of the existing framework established by RCW 59.18.140 (the Residential Landlord-Tenant Act) and RCW 59.18.720 (statutory notice form requirements), creating a multi-layered compliance landscape that catches many landlords off guard.

Notice Period Requirements

The 90-Day Rule (RCW 59.18.140)

Washington law requires landlords to provide at least 90 days written notice before a rent increase takes effect on a month-to-month tenancy. This notice period is measured from the date the tenant receives the notice to the date the increase becomes effective.

The 90-day requirement applies to:

• Month-to-month rental agreements
• Tenancies that have converted to month-to-month after a fixed-term lease expires
• Any periodic tenancy without a defined end date

The 5-Day Mailing Rule (RCW 59.12.040)

When serving any notice by mail in Washington, 5 additional days are added to the notice period under RCW 59.12.040. Since HB 1003 now requires certified mail for rent increase notices, this means the practical calculation is:

90 days (statutory notice) + 5 days (mailing service) = 95 days minimum lead time

This means if you want a rent increase to take effect on August 1, you need to mail the certified notice no later than April 28 (95 days prior).

Fixed-Term Leases: A Different Rule

For fixed-term leases (e.g., a 12-month lease), rent increases generally cannot take effect during the lease term unless the lease itself contains a provision allowing mid-term increases. This is uncommon in standard residential leases.

The typical approach is:

1. Wait until the fixed-term lease is approaching expiration
2. Provide the rent increase notice with the new lease terms (or conversion to month-to-month at the new rate)
3. Ensure the notice period is satisfied before the new rate takes effect

If a fixed-term lease expires and converts to month-to-month, the standard 90-day (95-day for certified mail) notice requirement applies going forward.

HB 1217: Washington's Rent Cap

The Formula

HB 1217 establishes a maximum allowable rent increase calculated as:

7% + CPI-U (Seattle-Tacoma-Bellevue MSA) = Maximum increase, capped at 10%

The CPI component uses the most recent 12-month Consumer Price Index for All Urban Consumers (CPI-U) for the Seattle-Tacoma-Bellevue metropolitan statistical area as published by the Bureau of Labor Statistics.

Which Properties Are Covered?

HB 1217 applies to most residential rental units in Washington, but several exemptions exist:

Covered:

• Apartments and multifamily units built before February 1, 2005
• Single-family rental homes (with some exceptions)
• Manufactured housing communities
• Most residential rentals with 4+ units on the property

Exempt:

• Units built after February 1, 2005 (to avoid discouraging new construction)
• Subsidized housing where rents are set by government programs
• Owner-occupied properties with an accessory dwelling unit (ADU)
• Properties with fewer than 4 units (in some circumstances)
• Units that have undergone substantial rehabilitation meeting specific cost thresholds

No Banking Unused Increases

A common question from landlords: "If I only raise rent by 3% this year, can I raise it by 17% next year?" The answer is no. HB 1217 applies the cap independently to each 12-month period. Unused capacity does not carry forward.

Penalties for Exceeding the Cap

Landlords who impose rent increases exceeding the HB 1217 cap face:

• The excess portion of the increase is void and unenforceable
• Tenants may recover actual damages plus reasonable attorney fees
• The Attorney General may pursue enforcement actions
• Potential civil penalties

Certified Mail Requirements (HB 1003)

What Changed

Before HB 1003, Washington landlords could serve rent increase notices by regular first-class mail, personal delivery, or posting. HB 1003 added a requirement that rent increase notices must be sent by certified mail and that the mailing must originate from within Washington State.

The Washington Postmark Requirement

This is the detail that trips up many out-of-state landlords and national property management companies: the certified mail must be posted from within Washington State. A notice mailed from a corporate office in Texas or a third-party mail service in Ohio may not satisfy the statutory requirement, even if it arrives in Washington.

RCW 59.12.040 governs how service by mail works in Washington. Combined with HB 1003's certified mail mandate, the practical effect is:

1. The notice must be sent via USPS Certified Mail
2. The postmark must show a Washington State origin
3. The mailing date plus 5 days starts the notice period clock

For a detailed guide on meeting the certified mail requirement, see our guide to certified mail for rent increase notices.

What Makes a Notice Legally Compliant

The Statutory Form (RCW 59.18.720)

Washington law specifies the content that must be included in a rent increase notice. Under RCW 59.18.720, the notice must contain:

• The current rent amount
• The new rent amount and the dollar amount of the increase
• The percentage of the increase
• The effective date of the increase
• Information about the rent cap and how it was calculated (if applicable)
• Notice of tenant rights, including relocation assistance eligibility
• The landlord's signature

Delivery Method Requirements

Under current Washington law (post-HB 1003), acceptable delivery methods for rent increase notices include:

Tacoma: Additional Requirements

Tacoma has the most stringent rent increase notice requirements of any city in Washington. Under Tacoma Municipal Code 1.95, landlords must provide 180 days notice via certified mail for rent increases, in addition to the state-required 95-day notice.

This means Tacoma landlords must send two separate notices for each rent increase:

1. 180-day certified mail notice (TMC 1.95) — Tacoma municipal requirement
2. 95-day certified mail notice (RCW 59.18.140 + HB 1003) — State requirement

Tacoma also has relocation assistance requirements for rent increases over 5%. For the complete breakdown, see our Tacoma rent increase notice guide.

Common Mistakes Landlords Make

1. Miscounting the Notice Period

The most common error is counting from the wrong date. The 95-day clock starts from the mailing date (postmark), not the date you prepare the notice or the date the tenant receives it. Count backward from your desired effective date.

2. Ignoring the Rent Cap

Many landlords, especially those managing smaller portfolios, are unaware of HB 1217 or incorrectly assume their property is exempt. Always verify exemption status before setting the new rent amount.

3. Mailing from Out of State

National property management companies and out-of-state landlords frequently send notices from their home state. Under HB 1003, this may invalidate the service. The postmark must show a Washington origin.

4. Using the Wrong Form

Washington requires specific content in rent increase notices under RCW 59.18.720. Using a generic "rent increase letter" that doesn't include the required disclosures about tenant rights, rent cap calculations, and relocation assistance can render the notice legally deficient.

5. Not Sending Individual Notices

For multi-resident leases, sending a single notice addressed to "all occupants" may not constitute proper service on each tenant. Best practice is to send a separate certified mail notice to each financially responsible tenant on the lease.

6. Failing to Keep Records

Certified mail receipts, tracking confirmations, and copies of the notice should be retained for at least 3 years. These records are your primary defense if a tenant challenges the rent increase.

Month-to-Month vs. Fixed-Term: A Summary

How NoticePM Simplifies Compliance

Managing rent increase notice compliance across a portfolio of properties means tracking dozens of deadlines, ensuring every notice meets statutory requirements, and coordinating certified mail from within Washington State. NoticePM automates this entire workflow:

• Automatic deadline calculation based on your desired effective date, including Tacoma's 180-day requirement
• Statutory form generation with all required disclosures pre-filled
• Certified mail from Washington State via our SendCertifiedMail.com integration, guaranteeing valid WA postmarks
• Per-tenant tracking with delivery confirmation and chain of custody documentation
• Rent cap verification to ensure your proposed increase complies with HB 1217

Key Takeaways

1. 95 days minimum: Mail your certified notice at least 95 days before the effective date (90 days + 5-day mailing rule).
2. Certified mail from WA: HB 1003 requires notices to be posted from within Washington State.
3. Check the rent cap: HB 1217 limits most increases to 7% + CPI (max 10%) for units built before 2005.
4. Use the statutory form: RCW 59.18.720 specifies required content. Generic letters are risky.
5. Tacoma is different: 180-day notice plus state 95-day notice. Two separate mailings required.
6. Keep records: Certified mail receipts and notice copies for at least 3 years.