Washington Annual Rent Increase Ceiling — HB 1217 CPI Calculation Guide (2026)

What Is Washington's Rent Increase Ceiling Under HB 1217?

In March 2019, Washington state enacted Substitute House Bill 1217 (HB 1217), one of the nation's first statewide rent control laws. This statute directly limits how much you can raise rent on existing tenancies. The law does not affect your ability to set initial rent when a new tenant moves in—only annual increases on renewing leases.

The legal cap is straightforward: 7 percent or the 12-month Seattle-Tacoma-Bellevue Consumer Price Index for All Urban Consumers (STB CPI-U), whichever is lower. This means even in years when inflation spikes well above 7%, you cannot charge more than 7%. Conversely, if inflation is extremely low, you are capped at that lower CPI figure.

This law applies to all residential tenancies in Washington state, regardless of how many units you own. It covers single-family homes, duplexes, apartment buildings, and manufactured homes. The law does not exempt newer construction, luxury properties, or any other category of housing. The only exception is tenancies that began before March 29, 2019—and even that exemption is narrowly defined.

Which Properties Are Covered by HB 1217?

HB 1217 applies to "residential tenancy agreements" as defined in RCW 59.18.030. This includes:

• Month-to-month tenancies
• Fixed-term leases that renew
• Any occupancy where a tenant pays rent in exchange for housing

The statute exempts only tenancies that began before March 29, 2019, but with a critical limitation: if you and your tenant sign a new lease agreement after that date, or if the lease renews after that date, the cap applies to future increases even if the original tenancy predates the law.

Exemptions that do NOT exist under HB 1217:

• New construction (no grace period)
• Recently renovated units
• Buildings with fewer than a certain number of units
• Single-family rentals (SFR)
• Luxury or high-rent properties
• Properties with low maintenance costs

If you own properties in Washington and rent to tenants, HB 1217 applies. Period.

Understanding the CPI-U Calculation

What Is the STB CPI-U?

The Seattle-Tacoma-Bellevue Consumer Price Index for All Urban Consumers is a government inflation measure published monthly by the U.S. Bureau of Labor Statistics (BLS). It tracks price changes for a basket of consumer goods and services—food, energy, housing, transportation, medical care, and more—across the Seattle metropolitan region.

For HB 1217 compliance, you use the 12-month CPI-U figure, not the monthly rate. This is the year-over-year percentage change in prices.

Where to Find the Official CPI-U Data

The BLS publishes STB CPI-U data monthly at bls.gov. The data is released around the 12th of each month for the previous month's figures. For rent increase calculations, you need the January release, which is the baseline for the calendar year.

The official series ID for Seattle-Tacoma-Bellevue CPI-U is APUU49A74714. You can search this on the BLS website or access historical tables directly.

Do not estimate or average CPI-U yourself. You must use the official BLS published figure. Using an incorrect, rounded, or misinterpreted number exposes you to tenant claims of overcharge.

The 12-Month Calculation Method

Here's how the calculation works in practice:

Example: Calculating the 2026 rent increase ceiling

You would use the 12-month STB CPI-U figure published by BLS in January 2026, comparing December 2024 to December 2025.

Let's say the BLS publishes that the STB CPI-U rose 4.2% over that 12-month period. Your rent increase ceiling for 2026 would be 4.2% (lower than the 7% statutory cap).

If instead the CPI-U rose 8.5%, your ceiling would be 7% (the statutory cap, since it's lower than 8.5%).

If the CPI-U fell 1.2% (deflation—rare but possible), your ceiling would be 0%, meaning you cannot legally increase rent that year.

STB CPI-U (12-month)	Your Legal Rent Increase Cap	Why
2.1%	2.1%	CPI-U is lower than 7% cap
5.8%	5.8%	CPI-U is lower than 7% cap
7.2%	7.0%	Statutory cap of 7% is lower
9.1%	7.0%	Statutory cap of 7% is lower
-0.3% (deflation)	0%	No increase allowed; rents may only stay flat

Step-by-Step Compliance Guide: Calculating and Serving Your Rent Increase

Step 1: Obtain the Current Year's CPI-U Data (January)

Timing: BLS releases January data around January 12th each year.

Action: Visit bls.gov, navigate to the "Databases, Tables & Calculators by Subject" section, and search for series APUU49A74714 (Seattle-Tacoma-Bellevue CPI-U). Record the 12-month percentage change.

Verification: Cross-check the figure with Washington state housing advocacy organizations or the Washington Tenants Union, which often publish the official ceiling in December/January for transparency.

Documentation: Save the official BLS data page or printout. If a tenant disputes your calculation later, you need proof you used the official figure.

Step 2: Compare CPI-U to the 7% Statutory Cap

Calculation: Take the lesser of (a) the STB CPI-U percentage or (b) 7%.

Example: If BLS publishes 5.3% CPI-U, your ceiling is 5.3%. If BLS publishes 8.1%, your ceiling is 7%.

Rounding: RCW 59.18.145 does not specify rounding rules. Industry practice rounds to one decimal place. If your calculation yields 5.34%, round to 5.3%. Do not round in your favor to reach a higher number.

Step 3: Calculate the Dollar Amount of the Increase

Formula: Current monthly rent × (ceiling percentage ÷ 100) = maximum allowable increase

Example: A tenant pays $1,200/month. The ceiling is 5.3%.

$1,200 × (5.3 ÷ 100) = $1,200 × 0.053 = $63.60

New rent: $1,200 + $63.60 = $1,263.60

Critical point: You cannot charge more than this amount. You may charge less or none at all, but exceeding the cap is a violation of RCW 59.18.145.

Step 4: Serve Written Notice 60 Days Before the Effective Date

Deadline: RCW 59.18.140 requires a 60-day written notice of rent increase. This is a strict requirement—serving notice 59 days before the increase effective date is not sufficient.

Content of notice must include:

• Current rent amount
• New rent amount
• Effective date of the increase
• Reason for the increase (optional but recommended for transparency)

Method of service: Notice can be served by:

• Personal delivery
• Certified mail, return receipt requested
• First-class mail (if tenant agrees in writing to electronic or mail service)
• Email (if tenant has consented to electronic notices)

Proof of service: Keep documented proof—certified mail receipt, email confirmation, or hand-delivery receipt. If a dispute arises, you must prove timely notice.

Step 5: Record and Document Everything

Store in your records:

• The BLS CPI-U figure used (with source documentation)
• Your calculation worksheet
• The notice sent to the tenant
• Proof of service (mail receipt, email read confirmation, etc.)

This documentation protects you if a tenant claims you overcharged or failed to provide notice.

Legal Requirements Under RCW 59.18.140 and RCW 59.18.145

RCW 59.18.140 — Notice of Rent Increase

This statute requires that any increase in rent be preceded by written notice given not less than 60 days before the effective date of the increase. The statute applies to month-to-month tenancies and lease renewals.

Key points:

• Notice must be in writing
• Must be received by the tenant at least 60 days before the new amount is due
• Failure to provide proper notice voids the increase
• If you attempt to collect rent at the new rate without proper notice, you may be liable for damages

RCW 59.18.145 — Rent Increase Limitation

This statute caps annual rent increases at the lesser of 7% or the 12-month STB CPI-U.

Exact language: "Except as provided in subsection (2) of this section, a landlord shall not cause to occur any of the following without prior written notice to the tenant, served in accordance with RCW 59.18.140: (a) An increase in rent to an amount which, over a 12-month period, is more than seven percent greater than the rent at the initiation of such 12-month period."

Subsection (2) exceptions (narrow):

• Tenancies beginning before March 29, 2019, are exempt (but only if they have not been renewed or renegotiated after that date)
• The cap does not apply if the tenant and landlord mutually agree in writing to a higher increase (but the tenant must have the opportunity to refuse)

The mutual agreement exception is controversial—some tenant advocates argue it is unenforceable due to the power imbalance. Do not rely on this exception without legal counsel.

Penalties for Violating the Rent Increase Cap

Tenant Rights and Legal Remedies

If you charge rent above the legal ceiling, a tenant can file a lawsuit against you under Washington's Residential Tenancy Act. The possible consequences are severe:

1. Actual Damages

The tenant can recover the actual overcharge—the difference between what they paid and the legal maximum. If they paid $1,300/month when the cap allowed only $1,263.60, they can recover $36.40 per month for every month of overage.

2. Treble Damages (Triple)

Under RCW 59.18.875, if a landlord "willfully" violates the rent increase cap or other RTA provisions, the tenant can recover up to three times the actual damages. Courts interpret "willfully" as knowingly exceeding the cap, even if you claim to have made a calculation error.

Example of treble damages: If a tenant overpaid $500 due to an illegal rent increase, they can sue for up to $1,500.

3. Attorney Fees and Court Costs

If the tenant wins, you must pay their attorney fees and court costs. In Washington, this can easily add $2,000–$5,000+ to your liability, depending on the complexity and duration of the case.

4. Other Equitable Relief

A court may order you to:

• Refund all overcharges
• Reduce rent to comply with the cap going forward
• Pay court costs and interest

Enforcement by Government Agencies

While tenant lawsuits are the primary enforcement mechanism, Washington's Attorney General's office and local prosecutors can investigate complaints of systematic rent overcharging. No explicit criminal penalty exists in RCW 59.18.145, but enforcement could involve:

• Civil investigations
• Cease-and-desist orders
• Restitution orders affecting multiple tenants
• Injunctions preventing further violations

Common Mistakes That Trigger Liability

Mistake #1: Using an Incorrect CPI-U Figure

The problem: You find a news article that says "inflation is 6%" and use that instead of the official STB CPI-U.

Why it's a violation: RCW 59.18.145 explicitly requires "the 12-month percentage change" in the "Seattle-Tacoma-Bellevue Consumer Price Index for All Urban Consumers." You must use the official BLS figure for that specific metro area.

The fix: Always pull data directly from bls.gov. Do not estimate or use national figures.

Mistake #2: Calculating Rent Increase as a Percentage of Total Annual Rent

The problem: You own a property with rent of $1,200/month. You calculate 5% of annual rent ($1,200 × 12 = $14,400; 5% = $720) and try to apply a $60 monthly increase.

Why it's wrong: The cap is applied to the monthly rent amount, not annualized.

Correct calculation: $1,200 × 5% = $60. New rent = $1,260.

Mistake #3: Serving Notice Less Than 60 Days Before the Increase

The problem: You hand-deliver a notice on March 15 stating the new rent takes effect April 14 (30 days later).

The consequence: The notice is void. The tenant does not have to pay the increased amount. If you attempt to evict for non-payment of the illegal increase, your eviction will fail, and you may face a counterclaim for damages.

Safe practice: Count calendar days carefully. Serve notice no later than 60 days before the first day of the month the increase is effective. When in doubt, serve at 75 days to avoid disputes.

Mistake #4: Combining Multiple Annual Increases

The problem: A tenant has been month-to-month for two years. You decide to raise rent by 7% for each of the last two years in one notice, all at once.

Why it violates the law: RCW 59.18.145 limits increases to 7% (or CPI-U) "over a 12-month period." You cannot stack multiple years' worth of increases into one raise. Each 12-month period allows one increase up to the ceiling.

The fix: Increases can only be applied once per 12-month period (usually annually on the lease anniversary).

Special Situations and Edge Cases

Tenancies That Began Before March 29, 2019

If your tenant's original lease was signed before March 29, 2019, the rent cap does not apply to that initial tenancy—but only if the lease has not been renewed or modified since that date.

Critical timing issues:

• If the tenant's lease expired and you signed a new lease renewal agreement after March 29, 2019, HB 1217 applies to all future increases
• If you and the tenant agree in writing to modify the lease after March 29, 2019 (even minor changes), some courts may view this as a new tenancy subject to the cap
• Month-to-month tenancies that began before March 29, 2019, but have continued rolling month-to-month after that date, are subject to the cap

Safe practice: If you are unsure whether a pre-2019 tenancy is exempt, assume the cap applies. This is the conservative compliance approach.

Furnished vs. Unfurnished Units

HB 1217 makes no distinction between furnished and unfurnished rentals. The cap applies equally to both.

Rent Decreases

If you voluntarily decrease rent (or the CPI-U is negative and the cap becomes 0%), you must still provide written notice, though the 60-day rule is typically interpreted as applying to increases only. Document the decrease in writing for clarity.

Unit-Specific Rent Increases for Repairs or Capital Improvements

Washington law distinguishes between "rent" and permissible charges for specific services or capital improvements. However, HB 1217 applies to the base rent amount. Any increase to base rent is subject to the cap, regardless of the stated reason.

Some landlords attempt to argue that rent increases for "capital improvement recovery" fall outside HB 1217. This argument has not prevailed in Washington courts. If you raise the monthly rent amount, the cap applies.

If you want to recoup costs for major repairs, consult an attorney about whether a separate, itemized charge (not labeled as "rent") would be permissible under your lease and Washington law. This is a gray area requiring legal guidance.

How to Stay Compliant Year-Round

Create an Annual Rent Increase Checklist

Use this checklist each January to ensure compliance:

• ☐ Obtain the current year's STB CPI-U figure from BLS (published mid-January)
• ☐ Document the source (bls.gov, series APUU49A74714)
• ☐ Compare CPI-U to 7% and identify the lower figure
• ☐ Calculate the dollar increase for each property (current rent × cap %)
• ☐ Prepare individual rent increase notices with all required information
• ☐ Ensure effective date is at least 60 calendar days away from service date
• ☐ Serve notices via certified mail, email (if tenant consented), or hand delivery
• ☐ Obtain and file proof of service for each notice
• ☐ Store all calculations and documentation for at least 3 years
• ☐ Update lease management system (if using software) with new rent amounts

Use Compliance Software to Track Rent Increases

LeaseBase's lease operations module automates rent increase tracking and ensures you apply the correct cap each year. The platform integrates CPI data and can flag if you attempt to increase rent beyond the legal ceiling, reducing calculation errors and liability.

Alternatively, LeaseBase's compliance engine provides state-specific rent control rules and notifies you of compliance deadlines, including the 60-day notice requirement.

Maintain Documentation

For each rent increase, file and retain:

• BLS CPI-U data (screenshot or printout)
• Calculation worksheet with old rent, percentage, new rent
• Notice sent to tenant (copy)
• Proof of service (certified mail receipt, email read receipt, etc.)

If a tenant later disputes the increase, you have documentary evidence that you acted correctly. This evidence significantly strengthens your position if the case goes to court.

Regional Considerations: Does the Cap Vary by County or City?

No. HB 1217 is a statewide statute. The rent increase ceiling is uniform across all of Washington and is based on the Seattle-Tacoma-Bellevue CPI-U. Even if you own properties in Spokane, Tacoma, or rural eastern Washington, you use the same STB CPI-U figure.

Some Washington cities have considered local rent control ordinances, but as of 2026, no municipality has implemented rent control rules stricter than HB 1217. Always check with your city clerk's office if you own properties in a major city, as this could change.

Frequently Asked Questions

Q: Can I increase rent twice in one year if I use different justifications (e.g., "first increase for inflation, second for capital improvement")?

A: No. HB 1217 limits rent increases to the cap amount "over a 12-month period." You cannot circumvent this by dividing the increase into multiple smaller increases or justifying them differently. The statute applies to the total rent amount charged, regardless of reasoning. Each 12-month lease anniversary allows one increase up to the cap.

Q: What if the BLS doesn't publish CPI-U data for some reason, or there's a delay?

A: The BLS publishes CPI-U data reliably every month. If there is an extreme government disruption or data anomaly, contact a Washington housing law attorney immediately. Do not estimate or use alternative indices without legal guidance. The safer approach is to delay serving increase notices until official data is available.

Q: If my tenant agrees in writing to an increase above the cap, is it legal?

A: This is disputed. RCW 59.18.145(2) suggests that mutual written agreement can override the cap, but tenant advocates argue this violates the statute's purpose and creates unequal bargaining power. Courts have not definitively ruled. The safest approach is to never exceed the cap, even with written tenant consent. If you believe a mutual agreement is necessary for your specific situation, consult an attorney before proceeding.

Q: How does HB 1217 affect security deposits or other fees?

A: HB 1217 applies only to "rent"—the base monthly housing payment. It does not limit your ability to charge security deposits, pet fees, parking fees, or other permissible charges separately. However, you cannot disguise a rent increase as a new fee. If you suddenly charge a new "facility fee" of $50/month that is actually compensating you for housing, a court may deem it a rent increase subject to the cap.

Q: What should I do if I accidentally charged rent above the cap for several months?

A: Immediately stop the overcharge and notify the tenant of a rent adjustment downward to comply with the cap. Offer to refund or credit the overcharged amounts. Consult an attorney before deciding on the exact refund terms. Proactive remediation may reduce a tenant's damages claim, though you remain liable for the overcharge period.

Looking Ahead: Recent Changes and Legislative Updates

HB 1217 has been in effect since 2019. As of October 2026, the statute remains unchanged in its core rent increase limit and CPI-U calculation method. However, monitor the Washington State Legislature for proposals that could:

• Lower the 7% cap further
• Expand exemptions
• Increase penalties for violations
• Change the CPI index used (though this is unlikely)

Landlord and tenant advocacy groups regularly propose amendments. Staying informed protects you from sudden compliance surprises.

Key Takeaway: Compliance Requires Precision

Calculating and serving a compliant rent increase under HB 1217 requires three precise steps: (1) using the official STB CPI-U figure, (2) applying the lower of that figure or 7%, and (3) serving written notice at least 60 days before the effective date. Missing any of these steps exposes you to actual damages, treble damages, and attorney fees.

If you manage multiple properties or have high-value leases, a single miscalculation can cost thousands. Automating this process with compliance-tracking software—like LeaseBase's platform—reduces human error and ensures timely notice service.

Review LeaseBase's compliance features to see how self-managing landlords are eliminating rent increase errors and staying on top of state-specific deadlines.

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Disclaimer: This article is for informational purposes only and does not constitute legal advice. Consult a qualified attorney for guidance specific to your situation. Rent control laws are complex and subject to change. This article reflects Washington law as of October 2026 and should be verified against current statutes before taking action.