Washington Rent Cap: HB 1217, 7% + CPI, and the 10% Ceiling
Short answer
Washington cap: maximum increase = min(7% + CPI, 10%), and no increase is allowed in the first 12 months of a tenancy (HB 1217, RCW 59.18.700). Example: $2,000 rent at 2% CPI caps at $2,180; at 4% CPI the 10% ceiling caps it at $2,200. Check city rules too.
Last verified: 2026-10-25. This is general information, not legal advice. City ordinances may be stricter and may override state rules. Check the official source for your city and state before acting.
Verified state rent caps
| State | Verified cap | Source |
|---|---|---|
| California | Maximum increase = min(5% + CPI, 10%) per 12 months, for covered properties | AB 1482, Civil Code 1947.12 |
| Washington | Maximum increase = min(7% + CPI, 10%); no increase in the first 12 months | HB 1217, RCW 59.18.700 |
| All other states | Check official source | No verified state cap is used on this site for other states |
Washington’s statewide rent stabilization law, HB 1217 (RCW 59.18.700), limits how much rent can rise and when it can rise at all. This guide explains the formula — the lower of 7% plus CPI and 10% — the ban on any increase in the first 12 months, and the city-ordinance check that still matters even when the state formula is clear.
The formula: min(7% + CPI, 10%)
Under HB 1217, the maximum annual increase is the lower of 7% plus CPI and 10%. Worked examples make the ceiling concrete. With $2,000 rent and 2% CPI, 7% + 2% = 9%, so the maximum rent is $2,000 × 1.09 = $2,180. With $2,000 rent and 1% CPI, the maximum is $2,070. With $2,000 rent and 4% CPI, 7% + 4% = 11% would exceed the ceiling, so the cap binds at 10% and the maximum is $2,200. Always use the CPI figure and definition your official source specifies for this statute — a national inflation headline is not necessarily the right CPI input.
No increase in the first 12 months
HB 1217 also provides that there is no rent increase in the first 12 months of a tenancy. This is a timing rule, not a percentage rule: even a small increase within the first year is barred, regardless of whether it would fit the 7% + CPI formula. If you moved in on 1 October 2025, the earliest a rent increase could take effect under this rule would be after 1 October 2026, subject to notice and any other applicable rules. Landlords should note the 12-month anniversary before serving any increase notice, and tenants who receive an increase notice in the first year should check the tenancy start date against the notice’s effective date.
Coverage, notice, and local ordinances
As with California, coverage matters: the statute’s scope, any exemptions, and the notice required for an increase must all be checked in the official source. A notice that states the wrong old rent, new rent, or effective date, or that gives too little notice, can be defective even if the percentage fits the cap. And city ordinances may be stricter and may override state rules — a Washington city may have its own rent rules, notice periods, or protections that change the answer for a particular home. Check both the state statute and your city’s official housing pages before concluding an increase is lawful or unlawful.
Checking an increase step by step
- Note the tenancy start date — was the increase proposed within the first 12 months?
- Note the current rent, the proposed rent, and the percentage increase.
- Find the correct CPI figure from the official source and apply min(7% + CPI, 10%).
- Check the notice: old rent, new rent, percentage, effective date, and notice period.
- Check your city ordinance for a stricter cap or longer notice period.
If the increase exceeds the cap
Write to the landlord with your calculation, the CPI source, and the tenancy dates, and ask for the basis of the increase. Keep the notice and all correspondence. If the landlord insists on the higher rent, contact a local housing organization or seek qualified advice before deciding whether to pay under protest, withhold the excess, or take another step — the right course depends on the notice, the lease, and the current statute, and acting without advice can create a separate arrears dispute. A calculator result is a useful check on the arithmetic; it is not a legal ruling on coverage or notice.
Try the calculator
Check a Washington increase against the min(7% + CPI, 10%) formula.
Washington cap at every CPI level
As CPI rises, the two sides of the formula trade places: below 3% CPI the 7% + CPI side sets the cap, and from 3% on the 10% ceiling binds. The table below uses a $2,000 rent; the same percentages apply at any rent.
| CPI | 7% + CPI | Cap applied | Maximum rent on $2,000 |
|---|---|---|---|
| 0% | 7% | 7% | $2,140 |
| 1% | 8% | 8% | $2,160 |
| 2% | 9% | 9% | $2,180 |
| 3% | 10% | 10% | $2,200 |
| 4% | 11% | 10% ceiling | $2,200 |
| 5% | 12% | 10% ceiling | $2,200 |
| 6% | 13% | 10% ceiling | $2,200 |
Notice what does not happen: the cap never rises above 10% under the state formula, however high CPI goes. A landlord who cites a CPI figure of 6% and proposes a 13% increase is not applying min(7% + CPI, 10%) correctly, because the “min” in the formula means the lower of the two figures. Equally, a CPI of 0% does not mean a 0% cap. The formula starts at 7% plus CPI, so even with no CPI movement the state formula allows up to 7%, subject to timing, notice, coverage, and city rules.
Worked examples at different rent levels
Percentages can feel abstract until they are turned into dollars at your rent level. The examples below keep the arithmetic visible so you can repeat it with your own figures: allowed increase equals old rent multiplied by the cap percentage, and maximum rent equals old rent plus that increase.
| Rent | CPI | Cap | Allowed increase | Maximum rent |
|---|---|---|---|---|
| $1,200 | 2% | 9% | $108 | $1,308 |
| $1,800 | 2.5% | 9.5% | $171 | $1,971 |
| $2,500 | 4% | 10% ceiling | $250 | $2,750 |
| $3,400 | 1% | 8% | $272 | $3,672 |
Take the $1,800 example in full. CPI of 2.5% gives 7% + 2.5% = 9.5%. Nine and a half percent of $1,800 is $171, so the maximum is $1,971. A proposal of $1,980 would be $9 over the state formula. Small overages still matter, because they compound: $9 a month is $108 a year, and next year's percentage will be worked out on the higher base. Take the $2,500 example the other way. With CPI of 4%, 7% + 4% = 11%, but the ceiling cuts it to 10%, so the allowed increase is $250 and the maximum is $2,750. A proposal of $2,775, which is an 11% rise, exceeds the state formula by $25 a month even though it matches 7% + CPI before the ceiling is applied.
The first 12 months: date examples
The first-12-months rule is a calendar question, and calendar questions are best answered with dates written down. The table below assumes the tenancy began on the date shown; if your tenancy began on a different date, shift the whole row by the same amount. The key comparison is always between the tenancy start date and the increase's effective date.
| Tenancy began | First 12 months end | Example increase effective date | Result under the timing rule |
|---|---|---|---|
| 1 October 2025 | 1 October 2026 | 1 September 2026 | Barred: still within the first 12 months |
| 15 March 2025 | 15 March 2026 | 15 February 2026 | Barred: still within the first 12 months |
| 1 June 2025 | 1 June 2026 | 1 July 2026 | Not barred by timing alone: effective after 12 months, cap and notice still to check |
Two points in that table deserve emphasis. First, a notice delivered before the anniversary is not automatically the same as an increase effective before the anniversary, and vice versa. Record both the delivery date and the effective date, and check the official source for how they interact. Second, passing the 12-month mark does not make any percentage lawful. An increase effective after the anniversary still has to fit min(7% + CPI, 10%), still needs proper notice, and still has to survive the city check. Timing is a gate, not a pass.
Washington compared with California
Washington and California share the same shape of formula — a base percentage plus CPI, capped at 10% — but the base percentages differ, so the same rent and the same CPI give different maximums. That difference is worth seeing in dollars, because tenants and landlords who move between the two states often carry the wrong figure with them.
| Rent and CPI | California: min(5% + CPI, 10%) | Washington: min(7% + CPI, 10%) | Difference |
|---|---|---|---|
| $2,000, CPI 2% | 7%, maximum $2,140 | 9%, maximum $2,180 | $40 a month |
| $2,000, CPI 4% | 9%, maximum $2,180 | 10% ceiling, maximum $2,200 | $20 a month |
| $2,000, CPI 6% | 10% ceiling, maximum $2,200 | 10% ceiling, maximum $2,200 | No difference: both capped |
At low CPI, Washington's higher base percentage gives a higher maximum. At high CPI, the shared 10% ceiling erases the difference entirely. The practical lesson is to run the formula for your own state rather than borrowing a neighbor's answer, and to re-run it when the CPI figure changes rather than reusing last year's maximum. A maximum that was correct last year, with a different CPI, is not evidence for this year's increase.
What the Washington cap does not tell you
The formula alone won’t settle your case. It won’t tell you if your home is exempt, what notice you were owed, which CPI figure counts, or whether your city caps rent lower — check those four things in the official source before you act. It does not answer questions about increases after the first year beyond the percentage formula itself — for how often increases may occur, check the official source rather than assuming an annual pattern. It does not cover any other state's rules, and it does not decide disputes about the condition of the property, the lease terms, or the history of the tenancy. If any of those questions decides your case, the formula alone is not enough, and a local housing organization or qualified professional is the next step.
Sources
- Washington HB 1217, RCW 59.18.700 — maximum increase min(7% + CPI, 10%); no increase in the first 12 months.
- California AB 1482, Civil Code 1947.12 — included only for the comparison table: min(5% + CPI, 10%) per 12 months for covered properties.
- For coverage, exemptions, notice rules, the applicable CPI definition, and city ordinances: Check official source — the Washington State Legislature's official site and your city's official housing pages.
Frequently asked questions
What is Washington’s rent cap?
The lower of 7% plus CPI and 10%, under HB 1217 (RCW 59.18.700).
Can rent rise in the first year in Washington?
No. HB 1217 bars any increase in the first 12 months.
What if CPI is high?
The 10% ceiling binds. For example, 7% + 4% CPI = 11%, capped at 10%.
How do I find the right CPI figure for Washington?
Use the CPI figure and definition specified by the official source for HB 1217. Do not substitute a national inflation headline, and keep a note of the figure and where you found it so the calculation can be checked.
Does the 10% ceiling ever not apply in Washington?
Under the state formula, no: the maximum is the lower of 7% + CPI and 10%, so it never exceeds 10%. A stricter city rule could set a lower maximum, but not a higher one under this formula.
What date counts as the start of the tenancy?
Check your lease and your move-in records for the tenancy start date, and compare it with the increase's effective date. If the two dates are disputed, that dispute has to be resolved before the timing rule can be applied.
What if the notice arrives before 12 months but takes effect after?
Record both the delivery date and the effective date, and check the official source for how notice and effective dates interact. Do not assume either date alone decides the question.
Does the Washington cap apply to every property?
Check the official source for the statute's scope and any exemptions. This guide states the formula, not a coverage decision for any particular home.
Can a landlord make up a missed year with a larger increase later?
Check the official source. Do not assume a catch-up increase is allowed, because the formula for the later increase still has to be applied on its own terms.
Same warning as above: this is general information, not legal advice — check the official source for your city and state.
Last updated: 2026-10-25. Last verified for state rules: 2026-10-25.