Constitutional Amendment: Uniformity & Broad Definition of Property

In 1930, the current uniformity clause was adopted (Amendment 14). This amendment provided that (1) all taxes on the same class of property shall be uniform within the territorial limits of the authority levying the tax and (2) real estate constitutes one class. The amendment also provided that property included everything, whether tangible or intangible, subject to ownership.

Governor Vetoes Income Tax Package

The legislature's Income Tax proposal was vetoed by Republican Governor Roland H. Hartley. The proposals imposed a net income tax on both personal and corporate income.

Voters Approve Statewide Income Tax

70% of voters approved a graduated progressive income tax ranging from 1% to 7% on annual income for individuals and corporations. The policy started at incomes 0-$1,000 at a rate of 1%, with a top rate of $12,000 ($285,000 in today's dollars) at 7%.

Court Invalidates Income Tax

The Supreme Court struck down the graduated net income tax in Culliton v. Chase, 174 Wash. 363 (1933), holding that income was property because property included everything subject to ownership. The graduated tax was therefore subject to the uniformity clause, violating uniformity because not all income was taxed in the same amount.

Voters Reject HJR 12 Constitutional Amendment

Legislature passed HJR 12, a constitutional amendment authorizing a graduated net income tax. At the 1934 election, the voters rejected HJR 12, authorizing the graduated net income tax, that was adopted in the 1933 session by a vote of 134,908 for to 176,154 against.

Revenue Act of 1935

In 1935, the Legislature enacted and governor signed both individual and corporate net income taxes. The corporate income tax was enacted in HB 237, the Revenue Act of 1935, along with a state sales tax on consumers, a cigarette tax, and today's Business and Occupations tax. The net income tax on individuals was by separate bill.

Court Strikes Down Income Taxes

The court in Jensen v. Henneford, 185 Wash 209 (1936), struck down the individual income tax enacted in 1935, again based on the constitutional requirement of uniformity of property taxes. The corporate income tax that was enacted in 1935 was likewise struck down in Petroleum Navigation Company v. Henneford, 185 Wash 495 (1936).

Voters Reject SJR 7

The Legislature adopted and voters subsequently rejected, Senate Joint Resolution 7, Voters defeat SJR 7, 78% to 22%.

Voters Reject SJR 5

The Legislature returned with a new constitutional amendment effort in 1937, referred to voters as SJR 5. Voters did not approve the measure in 1938 (67% to 33%). The result kept the constitutional uniformity barrier in place.

Voters Reject HJR 4

In 1941, the Legislature referred another constitutional amendment to voters. The 1942 election again produced a “no” vote (66% to 34%). Washington continued to rely on other revenue sources rather than a graduated income tax.

Court Invalidates Corporate Privilege Tax

The Legislature passed a corporate excise tax in 1951, levying a net income tax on corporate profits. In Power v. Huntley (1951), the court invalidated a 4% tax. The court reiterated that a tax on income is a tax on property under Washington’s constitution. It also raised uniformity concerns because the tax did not apply across competing business forms.

Voters Reject Income Tax Amendment

The proposal, adopted by the Legislature in 1969, would have allowed a flat-rate income tax and contemplated a future shift to graduated rates under stricter approval rules. Voters rejected the amendment in 1970 (68% to 32%). The result again left the state constitution unchanged on income taxation.

Voters Reject Graduated Income Tax Amendment

The Legislature adopted the proposal in 1973 and referred it to voters for the 1974 election. The measure combined a graduated structure for individuals with a flat-rate approach for corporations. Voters rejected the amendment (78% to 22%), continuing a decades-long pattern of “no” votes on authorizing income taxes.

Voters Reject Initiative 314

Initiative 314 would have created a 12% corporate privilege fee tied to net income. The measure was defeated at the ballot in 1975 (67% to 33%). The outcome reinforced how difficult it has been for income-based tax proposals to advance statewide.

Voters Reject Initiative 435

Initiative 435 proposed a 10% corporate privilege fee on net income. Washington voters rejected the measure in 1982 (66% to 34%). The defeat continued the trend of ballot-box resistance to income-tax-style proposals.

Voters Reject Initiative 1098

Initiative 1098 proposed an excise tax on annual personal income above $200,000 for individuals or $400,000 for joint filers. The measure was defeated in 2010. The result extended Washington’s long-running history of statewide votes rejecting income-tax proposals.

Legislature Approves Initiative 2111

Initiative Measure No. 2111 prohibited the state, counties, cities, and other local jurisdictions from imposing or collecting income taxes, defined as having the same meaning as “gross income” in the Internal Revenue Code. The vote was 76 to 21 in the House, and 38 to 11 in the Senate.

Legislature Introduces Millionaire's Income Tax

Senate Bill 6346 would institute a tax on personal incomes above $1 million.

Governor Signs the Income Tax; Initiative 645 Heads to Voters

The Legislature passed SB 6346 in March and Governor Ferguson signed it on March 30, 2026: a 9.9% tax on personal income above $1 million, taking effect in 2028. On July 15, the Secretary of State certified Initiative 645, which would repeal the tax, for the November 3, 2026 ballot. A separate constitutional challenge under the uniformity clause is working its way toward the Washington Supreme Court.