Gross income-tax revenue by fiscal year, by estimate

What this dataset measures

Initiative 645 (Nov. 3, 2026 ballot) would repeal the tax. Campaigns cite $11.4 billion, $13 billion and $300 billion for what repeal would cost. Those figures come from different estimates and different windows of years; this dataset puts every official estimate on the same fiscal-year basis so readers can see which window each figure covers.

Geography

Washington, United States

Unit of observation

One estimate of gross income-tax revenue for one state fiscal year.

Update cadence

Updated when ERFC issues a new revenue forecast (next: November 2026) or OFM issues a new fiscal note.

Curator

FactHub Research Team

Curated data tables

Gross income-tax revenue by fiscal year, by estimate

Each official estimate of gross collections from the 9.9% tax, by state fiscal year.

Unit of observation: One estimate for one state fiscal year

estimates_by_fy.csv text/csv · 3.4 KB (3,467 bytes)

All 16 rows 8 columns Download the file

All 16 rows

estimate_id	estimate_name	publisher	published_date	fiscal_year year	gross_income_tax_musd millions of US dollars, cash basis	value_type	note
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2029	2698	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2030	3732	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2031	3167	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2032	3297	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2033	3439	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2034	3591	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
fiscal-note	ESSB 6346 fiscal note (Mar 2026)	OFM / Dept. of Revenue	2026-03-16	2035	3753	observed	Tax on Income line, account 001, cash basis; static (no behavioral response).
erfc-june	ERFC forecast (June 2026)	Economic and Revenue Forecast Council	2026-06-26	2029	2698	observed	Individual Income Tax, 2027-29 biennium, June 2026 forecast column (ERFC Sept 2026 publication, Table 3.7); only FY29 has collections.
erfc-june	ERFC forecast (June 2026)	Economic and Revenue Forecast Council	2026-06-26	2030	3732	derived	June Fair Start transfer for FY31 ($251.6M - $65.0M = $186.6M) divided by 5%.
erfc-june	ERFC forecast (June 2026)	Economic and Revenue Forecast Council	2026-06-26	2031	3167	derived	2029-31 income-tax forecast ($9,435M - $2,536M = $6,899M) less FY30.
ofm-fis	OFM fiscal impact statement for I-645 (Jul 2026)	Office of Financial Management	2026-07-23	2029	3108	observed	Table 1 total revenue loss, state general fund + Fair Start for Kids account. Excludes $0.414M federal funds in FY27-28.
ofm-fis	OFM fiscal impact statement for I-645 (Jul 2026)	Office of Financial Management	2026-07-23	2030	4432	observed	Table 1 total revenue loss, state general fund + Fair Start for Kids account. Excludes $0.414M federal funds in FY27-28.
ofm-fis	OFM fiscal impact statement for I-645 (Jul 2026)	Office of Financial Management	2026-07-23	2031	3892	observed	Table 1 total revenue loss, state general fund + Fair Start for Kids account. Excludes $0.414M federal funds in FY27-28.
erfc-sept	ERFC forecast (Sept 2026)	Economic and Revenue Forecast Council	2026-09-25	2029	3503.1	observed	Individual Income Tax, 2027-29 biennium, Sept 2026 forecast (ERFC publication Table 3.7); only FY29 has collections. Fair Start FY30 transfer $175.2M / 5% = $3,504M agrees.
erfc-sept	ERFC forecast (Sept 2026)	Economic and Revenue Forecast Council	2026-09-25	2030	5032	derived	ERFC Fair Start transfer for FY31 ($251.6M) divided by 5%. Our calculation; +/- $2M rounding.
erfc-sept	ERFC forecast (Sept 2026)	Economic and Revenue Forecast Council	2026-09-25	2031	4403	derived	2029-31 income-tax forecast ($9,435M, WRC 9/25/2026) less FY30. Our calculation. ERFC Table 3.9 "Other (including Individual Income Tax)" FY30 $5,089.0M and FY31 $4,461.8M agree after about $57-59M of other revenue.

8 field definitions

Field	Type	Meaning	Units	Value type
estimate_id	string	Short id of the estimate.	—	observed
estimate_name	string	Estimate and its publication month.	—	observed
publisher	string	Agency that published the estimate.	—	observed
published_date	date	Date the estimate was adopted or published.	—	observed
fiscal_year	integer	State fiscal year ending June 30 of this year.	year	observed
gross_income_tax_musd	number	Gross income-tax collections (before the 5% Fair Start transfer and before any offsetting tax relief).	millions of US dollars, cash basis	estimated
value_type	string	"observed" if printed in the source, "derived" if our calculation.	—	derived
note	string	Exact line in the source, or the calculation for a derived value.	—	observed

Supporting files

Source snapshots, manifests, quality reports, documentation, and other materials used to produce or review this release.

• build.js Transformation manifest · text/javascript · 8.3 KB (8,539 bytes)

  Node.js script that holds every input value with its source and writes the three tables and all saved-analysis results.

• content-parts.json Documentation · application/json · 30.8 KB (31,561 bytes)

  Sources, table definitions, saved analyses and statements of this release, as JSON (the same values the dataset page shows).

Sources

1. Multiple Agency Fiscal Note Summary, ESSB 6346 (2026), Tax on millionaires, OFM Fiscal Note package 77653 Fiscal note gross "Tax on Income" line and whole-bill net revenue by fiscal year, FY2026-2035.

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. Prepared by the Department of Revenue and published by the Office of Financial Management for the Legislature in March 2026. States its assumption that affected taxpayers do not reduce taxable income.

2. Fiscal Impact Statement for Initiative 645, Office of Financial Management (July 2026) Revenue lost by fiscal year if I-645 passes (Table 1).

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. Required by RCW 29A.72.025 and printed in the voters' pamphlet. Covers SFY2027-2031 only and excludes effects that depend on future legislative action.

3. Washington State Economic and Revenue Forecast, September 2026 (Vol. LXII, No. 3), Economic and Revenue Forecast Council Individual Income Tax 2027-29 biennium forecast, June and September (Table 3.7); General Fund-State detail by fiscal year (Table 3.9).

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. ERFC is the state's official, bipartisan revenue forecaster; its forecast is the legal basis for the state budget. Forecast adopted September 25, 2026.

4. Revenue Review, September 25, 2026, Economic and Revenue Forecast Council Fair Start for Kids Account forecast by fiscal year (5% of prior-year income-tax collections): FY2030 $175.2 million, FY2031 $251.6 million; June-to-September revisions.

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. Official ERFC presentation of the September 2026 revenue forecast.

5. Outlook for the Enacted 2026 Supplemental Omnibus Operating Budget (ESSB 5998), April 22, 2026, Economic and Revenue Forecast Council NGF-O projected ending balance by fiscal year and biennium.

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. The four-year balanced-budget outlook required by RCW 43.88.055, adopted by ERFC.

6. Enacted 2026 Supplemental Budget Outlook Methodology, April 22, 2026, Economic and Revenue Forecast Council Revenue legislation counted in the outlook (ESSB 6346: -$46,400 thousand in 2025-27, +$2,309,180 thousand in 2027-29); non-mandatory FY2029 expenditures for free school meals ($140 million) and city and county fiscal health ($200 million).

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Government. Methodology document accompanying the adopted outlook.

7. Revenues for 2025-27 and 2027-29 are still lower than expected when 2026 budget was adopted, but income tax revenue estimates are increased going forward, Washington Research Council (Sept. 25, 2026) September 2026 income-tax forecast by biennium ($3.503 billion 2027-29, $9.435 billion 2029-31) and change from June.

   Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Advocacy group. Business-funded nonpartisan research group that has published analysis critical of the income tax; here it only restates ERFC forecast figures, which match ERFC Table 3.7 for 2027-29.

8. New brief: I-645: Repealing the State Individual Income Tax, Washington Research Council (Sept. 22, 2026) States that no current appropriations rely on the revenue and that the current outlook assumes $2.698 billion of income-tax revenue in 2027-29.

   Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Advocacy group. Business-funded nonpartisan research group; it takes no position on I-645 in this brief.

9. 2026 General Election Voters' Pamphlet, Initiative Measure No. IP26-645, Washington Secretary of State Arguments for and against I-645 and rebuttals, written by each campaign committee.

   Retrieved October 21, 2026. Public record (Washington State government work). Figures quoted with attribution; source file linked, not rehosted.

   Reliability: Party to the dispute. Has a stake in this finding. The Secretary of State prints the statements as submitted; each argument is written by the committee for or against the measure and is not fact-checked by the state.

10. No on 645 campaign home page Campaign wording of the $13 billion claim.

    Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

    Reliability: Party to the dispute. Has a stake in this finding. Official site of the committee opposing I-645, funded mostly by labor unions (PDC).

11. Post by Rep. Pramila Jayapal (@PramilaJayapal) on X, Sept. 26, 2026 Jayapal's "$300 billion tax break" statement. Free copy

    Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

    Reliability: Party to the dispute. Has a stake in this finding. Personal campaign account of the U.S. representative for WA-07, who opposes I-645. x.com blocks automated reading; the archived copy of X's own embed record shows the same text and that the post was not edited.

12. Heywood says I-645 fiscal impact statement is premature, vows court challenge, Seattle Red (July 19, 2026) Brian Heywood quoted on K-12 funding.

    Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

    Reliability: News report. Conservative talk-radio station website; quotes Heywood from an on-air interview on The Jason Rantz Show.

13. The millionaires tax is on the WA ballot this fall. Both sides make their case, KUOW (Oct. 8, 2026) Interview transcript excerpts with Rian Watt (No) and Jaime Herrera Beutler (Yes).

    Retrieved October 21, 2026. All rights reserved (quoted under fair use). Figures quoted with attribution; source file linked, not rehosted.

    Reliability: News report. Seattle public radio station (NPR member); edited transcript of its Soundside program.

Limitations and reproducibility

Reproducible: All inputs are printed in the linked government documents and typed into build.js, which writes every table and saved-analysis result. Derived values (ERFC per-year split, outlook balance without the tax) are computed in build.js with the method in each row note.

• All estimates are static: they assume high earners do not change their behavior in response to the tax (the fiscal note says "affected taxpayers do not reduce taxable income").
• No collections exist yet. The first payments are due in April 2029; every value is a projection.
• ERFC publishes its income-tax forecast by biennium. The FY2030 and FY2031 split is our calculation from ERFC's 5% Fair Start for Kids transfers (5% of the previous fiscal year's collections), which ERFC publishes by fiscal year; rounding of the transfers to $0.1 million gives about +/- $2 million per year.
• The September 2026 2029-31 income-tax total ($9,435 million) is as reported by the Washington Research Council; ERFC's own Table 3.9 corroborates it only within a combined "Other (including Individual Income Tax)" row.
• OFM's fiscal impact statement counts revenue lost to the general fund plus the Fair Start for Kids account; it excludes $0.414 million of federal funds in FY2027-28 that this table leaves out.
• The tax faces a constitutional challenge (Petter v. State, Klickitat County Superior Court, filed April 9, 2026). If courts strike it down, actual revenue would be zero with or without I-645.