SB6346

Washington Passed the Income Tax It Spent Ninety Years Banning

Start with the wall. For over ninety years Washington has treated income as property under the state Constitution. That reading traces back to Culliton v. Chase, a 1933 state Supreme Court decision, and because property must be taxed uniformly and capped at one percent of value, a graduated income tax has been off the table. Every attempt to pass one has run into that wall. In 2024, the state added a second layer: Initiative 2111, a statewide ban on taxing "any form of personal income."

SB6346 is the state's answer to both. Here is what the enrolled text actually does.

1. It imposes a 9.9 percent tax on a household's Washington taxable income above a $1,000,000 standard deduction. The base is built on federal adjusted gross income. This is an income tax, measured by income. Not a wealth tax, not a tax on assets.
2. It amends Initiative 2111, the 2024 income-tax ban, to say that ban "does not apply" to this tax, so long as the deduction stays at least $1,000,000.
3. It declares itself "necessary for the support of the state government," which under Washington law blocks voters from challenging it by referendum.
4. It ties the popular parts to the tax. If a court strikes the 9.9 percent tax, the sales-tax breaks on diapers, personal care products, and some over-the-counter drugs, plus the small-business credits enacted alongside it, are canceled too.
5. It orders the Department of Revenue to keep implementing the tax "regardless of litigation."

Two numbers put the stakes in view. The state's own fiscal note estimates the tax reaches about 21,000 households and raises roughly $3.45 billion in its first full year of collection. That is a narrow base carrying a very large, and now permanent, piece of the state budget.

Get the label right, because the label is the whole fight. The state's defense is that this is an excise tax "measured by" income, the same theory that saved the capital gains tax in Quinn v. State in 2023. The challengers in Petter v. Department of Revenue say a broad 9.9 percent tax on all income is a tax on income, which runs straight into the ninety-year property rule. Call it a wealth tax and you hand the state the argument. Call it what it is, an income tax, and the ninety-year wall is still standing in the way.

One point needs to be precise, because getting it wrong would weaken the case. Amending a voter measure within two years normally takes a two-thirds supermajority. That rule does not apply here. Initiative 2111 was never approved at the ballot. The Legislature enacted it themselves in 2024, so lawmakers were free to amend it by simple majority, which is what they did. The constitutional vulnerability is not the I-2111 carve-out. It is the uniformity theory in Petter. The civic objection stands on its own: a legislature unwound a citizen income-tax ban by ordinary majority within two years of adopting it. The Constitution permits that. Voters are entitled to remember it.

Watch the trajectory, because it is the clearest part of the record. Capital gains excise tax in 2021. Upheld in Quinn in 2023. Income-tax ban passed, then repeal rejected, in 2024. A broad 9.9 percent income tax in 2026. A base that starts narrow and widens once the courts and the voters have been navigated is the pattern conservatives have warned about for years, and here it is on a four-year clock. The carve-out holds only "so long as" the deduction stays at $1,000,000. A future session can lower that number with the same simple majority that passed this bill.

The story is still moving. The referendum is dead: the state Supreme Court upheld the necessity clause in May 2026 and blocked it. The Petter lawsuit is live in Klickitat County Superior Court, seeking to invalidate the tax on the uniformity theory. And the voters are getting their say after all. On July 15, 2026, the Secretary of State certified Initiative 645 for the November 3, 2026 ballot, after Let's Go Washington submitted more than 500,000 signatures against a requirement of roughly 309,000 valid ones, with 82.3 percent of the sampled signatures verified. A yes vote repeals the 9.9 percent tax while keeping the family and small-business tax breaks in place, and bars local governments from imposing an income tax of their own. A no vote keeps the tax.

Voters will not read that question cold. Near the yes-or-no line, the ballot carries a separate statement the Attorney General's office drafts for measures that would reduce state revenue, a Public Investment Impact Disclosure. On I-645 it reads: "This measure would decrease funding for K-12 education, healthcare, human services, and higher education." That is not the question. It is a warning label the state gets to set beside the question, on the ballot, at the moment a voter decides. The framing that says a repeal takes money from schools is printed next to the box, and the framing that says the tax was never constitutional to begin with is not.

The defense is already funded. A committee called No on 645 launched on July 14, 2026 with Governor Ferguson taking part, and its public disclosure filings show its top backers are the government-worker unions with the most to gain from the spending: the Washington Education Association, the Washington Federation of State Employees, and several SEIU-affiliated funds, with SEIU alone in for $1,000,000 so far. The people who spend the revenue are paying to keep the tax that raises it.

The tax does not collect a dollar until 2029. The 2028 tax year is the first one it touches, and the first payments come due the following spring. Which means the whole thing, the ninety-year wall, the voter ban, the referendum shield, the poison pill, comes down to a single question the state spent a decade trying to keep off the ballot. In November, Washington voters get to answer it themselves.

This is our read of the bill. We encourage you to read it yourself and reach your own conclusions. The sources are public and cited below.