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Washington State Taxes

Summary

Comprehensive guide to Washington State taxes for founders, investors, and high earners — capital gains tax, the 9.9% income tax, QSBS treatment, and planning strategies.

📘 Washington State Tax Planning Guide for High Earners

Washington State Tax Planning Guide for Founders and High Earners

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Washington State Tax Policy for Startups

🚨 New — Updated April 4, 2026
Washington’s 9.9% Income Tax: What High Earners Must Do Before 2028
Governor Ferguson signed Washington’s 9.9% income tax into law. This guide covers the biggest planning strategies — QSBS, income timing, domicile planning, PTE elections, and AGI reduction — for founders, investors, physicians, and executives earning over $1M.
Read the Full Guide →
  1. The Full Tax Stack: What Founders Are Actually Facing
  2. The Capital Gains Tax (Already Law)
  3. The Millionaire Income Tax (Now Law)
  4. The QSBS Add-Back Bills: Stripping Section 1202
  5. Payroll Taxes: JumpStart, WA Cares & the Statewide Proposal
  6. The B&O Tax: What Startups Pay Today
  7. Washington’s Estate Tax
  8. The Combined Rate: 18%+ in Seattle
  9. How This Changes Behavior
  10. Planning Strategies for Washington Founders
  11. Will the Income Tax Survive a Court Challenge?
  12. Legislative Timeline & Key Dates

1. The Full Tax Stack: What Founders Are Actually Facing

Most commentary about Washington’s tax proposals treats each bill in isolation. That’s a mistake. The real story is the full stack of taxes the legislature is building — layer by layer, session by session — that collectively reach into every stage of a founder’s journey.

Three years ago, Washington was one of the most founder-friendly states in the country. No income tax. QSBS conformity. A startup ecosystem that was genuinely competitive with the Bay Area. The legislature is dismantling that advantage in real time.

There is no stage of the founder’s journey that Olympia isn’t reaching into.

2. The Capital Gains Tax (Already Law)

Washington’s capital gains tax is no longer a proposal — it’s settled law, upheld by the state Supreme Court and expanded in 2025. The current structure, effective January 1, 2025, uses a tiered rate:

The standard deduction is $250,000 (indexed annually; $278,000 for tax year 2025). Gains above the standard deduction up to $1 million are taxed at 7%. Gains above $1 million are taxed at 9.9%. Always confirm the current-year indexed amount with the Washington Department of Revenue.

The tax base starts with your federal net long-term capital gain. This is critically important for QSBS: because gain excluded under Section 1202 never enters your federal taxable income, it also falls out of the Washington tax base. In other words, under current law, if your QSBS exclusion works at the federal level, Washington doesn’t tax your QSBS gain.

This is a big deal. The median WA founder’s QSBS gain is far below the threshold at which a 7% or 9.9% rate kicks in. The difference between a 0% rate and a 7% rate on a $5 million gain is $350k.

So let’s be clear: Washington’s capital gains tax currently protects QSBS. But only because the legislature has not yet passed an add-back rule.

3. The Millionaire Income Tax (Signed Into Law March 30, 2026)

On March 12, 2026, the Washington legislature passed ESSB 6346, imposing a 9.9% tax on household income above $1 million. Governor Ferguson signed it into law on March 30, 2026. It takes effect January 1, 2028.

For a detailed breakdown — including how it works for founders selling stock, the marriage penalty, the constitutional fight ahead, and what you should be doing now — see: Washington's New Income Tax: What Founders, Investors, Athletes, and High Earners Need to Know

  • Income up to $1M: 0% (exempt — $1M standard deduction)
  • Income above $1M: 9.9%

Unlike the capital gains tax — which uses tiered brackets ($250k exempt, 7% on $250k–$1M, 9.9% above $1M) — ESSB 6346 is simpler: a flat $1M standard deduction, then 9.9% on all income above that threshold.

Want to see what this means for your specific income? Use the WA Income Tax Calculator →

Importantly, the income tax would apply to salary and bonus income. For founders with high W-2 earnings post-exit or from non-QSBS ventures, this is a direct hit.

For how the new tax applies to equity compensation — ISOs, NQSOs, and RSUs — see How Washington's New 9.9% Income Tax Applies to Stock Options and RSUs. For how the tax interacts with real estate gains and the capital gains tax exemptions, see Are Real Estate Gains Subject to Washington's New 9.9% Income Tax?.

4. The QSBS Add-Back Bills: Stripping Section 1202

Two bills introduced in the 2026 session — SB 6229 and HB 2292 — would have forced you to include QSBS gains in your Washington capital gains tax base, even if the federal exclusion under Section 1202 applies. Both bills died in committee and did not pass in 2026.

The sponsors were explicit: they believe Section 1202 is a loophole that should be closed. The bills did not even attempt to create a WA-specific exclusion. They would have simply added back the portion of gain excluded under Section 1202 and taxed it at 7% or 9.9%. While they did not pass this session, similar legislation is likely to be reintroduced in future sessions. This remains a live threat to watch.

If such a bill were passed, it would effectively wipe out the QSBS benefit in Washington. Founders who rely on QSBS to offset the cost of doing business in a high-cost market would lose their largest tax advantage.

This is why timing still matters. Right now, the capital gains tax is live, and the add-back rule is not. If you are considering an exit or a secondary sale of QSBS, the absence of an add-back rule is a planning advantage — but it could change in a future session.

5. Payroll Taxes: JumpStart, WA Cares & the Statewide Proposal

Seattle JumpStart Tax

Seattle already imposes the JumpStart payroll tax on companies with annual payroll expenses above $7 million. The tax rate is progressive, ranging from 0.7% to 2.4% depending on payroll size and employee compensation. It applies to employees who work at least 50% of their time in Seattle.

This tax has been in place since 2021 and primarily affects large tech companies. However, if your startup’s headcount and salaries grow rapidly, you could cross the $7 million threshold faster than you expect.

WA Cares Fund

The WA Cares Fund is a mandatory long-term care insurance program funded by a 0.58% payroll tax on all wages, with no Social Security wage base cap (unlike Washington Paid Family and Medical Leave). Originally scheduled to begin in January 2022, premium collection was delayed until July 1, 2023. Benefits first become payable July 1, 2026.

Founders with employees in Washington need to budget for this additional cost. Unlike JumpStart, this tax isn’t limited to Seattle; it applies statewide.

Proposed Statewide Payroll Tax

There have been discussions about a statewide payroll tax to fund various social programs. While no specific bill is on the table, the trend is clear: policymakers see payroll taxes as a revenue source that can be expanded beyond Seattle.

For more details, see Washington’s Proposed Statewide Payroll Tax: What Employers Need to Know.

6. The B&O Tax: What Startups Pay Today

Washington’s Business & Occupation (B&O) tax is a gross receipts tax. Unlike an income tax, it applies to your company’s gross revenue, regardless of profitability.

The B&O rate for service businesses (which includes most startups) was a flat 1.5% of gross receipts until October 1, 2025. Under HB 2081, the Service and Other Activities rate is now tiered based on the prior calendar year’s taxable income in that classification: 1.5% under $1M, 1.75% from $1M to $5M, and 2.1% above $5M. There are small business credits, but once your annual revenue exceeds $100,000, the credit phases out quickly.

For a startup with $2 million in gross revenue, the B&O tax liability would be $35,000 (1.75% of $2M under the current tiered service rate). This is in addition to any other taxes you owe.

Because the B&O tax is based on revenue, it hits unprofitable startups just as hard as profitable ones. This is especially painful for early-stage companies that are reinvesting every dollar into growth.

7. Washington’s Estate Tax

Washington has one of the highest estate tax rates in the country, with a top rate of 20%. The exemption is $3,076,000 for decedents dying in the first half of 2026 (still indexed under SB 5813). On July 1, 2026, SB 6347 resets it to exactly $3,000,000 and freezes it — the statute points back to a defunct CPI series, so it will not adjust for inflation going forward.

For founders whose wealth is tied up in private company stock, the estate tax can create liquidity issues for heirs. If your estate exceeds the exemption, your heirs could owe millions in tax even if they don’t have liquid assets to pay it.

Estate planning is essential for any founder with significant assets, whether or not you plan to remain in Washington.

Update: see Governor Ferguson Signs Estate Tax Rollback: Top Rate Returns to 20%.

8. The Combined Rate: 18%+ in Seattle

Let’s add up the layers:

  • Capital gains tax: 9.9% above $1 million
  • Income tax: 9.9% above $1 million
  • JumpStart payroll tax: up to 2.4% on compensation
  • WA Cares payroll tax: 0.58% statewide
  • B&O tax: 1.5% on gross receipts

If all these taxes apply, a founder in Seattle could face a combined marginal rate above 18% on certain income streams. And that’s before considering federal taxes.

For comparison, California’s top marginal income tax rate is 13.3%, and it doesn’t have a capital gains tax separate from the income tax. In other words, the combined state and local tax burden in Seattle could exceed that of Silicon Valley.

9. How This Changes Behavior

Taxes influence where founders choose to live, build companies, and realize gains. If Washington continues to layer new taxes on top of each other, we should expect to see:

  • Relocation of founders: Entrepreneurs may move to states with more favorable tax climates (e.g., Texas, Florida, Nevada).
  • Delayed exits: Founders may postpone liquidity events to avoid a near-term tax hit, especially if there’s a chance the tax landscape could improve.
  • Alternative structures: More use of offshore entities, trusts, or complex ownership structures to minimize WA tax exposure.

These decisions can have second-order effects on the local economy, including reduced investment in Seattle-based startups and a brain drain of talent.

10. Planning Strategies for Washington Founders

The 2028 effective date creates a genuine but closing window. Here are the key strategies to consider before the tax takes effect.

  • Domicile planning: what leaving Washington actually requires. Establishing residency in a no-income-tax state before a major liquidity event can eliminate the Washington income tax entirely — but only if done correctly. Washington uses a facts-and-circumstances domicile test, not just a day-count. Simply buying a home in Nevada or Florida and spending 183 days there is not enough. You must change your primary domicile: update your driver's license, voter registration, banking relationships, and professional ties. The closer you are to a large liquidity event, the more scrutiny a domicile change will face. Start early — ideally 12–18 months before the event — and document everything. See How to Change Your Washington Domicile to Avoid the Income Tax.
  • Stock option exercise timing: ISOs and NSOs before 2028. For founders and employees holding unexercised options, exercise timing matters significantly. ISO exercises before 2028 generate AMT exposure but no regular income tax — and no Washington tax. NSO exercises before 2028 generate ordinary income, but at a 0% Washington rate. After 2028, both create income potentially subject to the 9.9% tax above the $1M threshold. The right strategy depends on your strike price, current 409A value, AMT position, and proximity to an exit. See Stock Option Exercise Timing: Planning Before Washington's 2028 Income Tax.
  • Tax loss harvesting to stay below the $1M threshold. The income tax kicks in at $1M and applies to all household income above that threshold. Harvesting investment losses strategically in 2028 and beyond can keep your taxable income below or closer to the threshold. This works best for founders with diversified investment portfolios alongside their equity. See Tax Loss Harvesting to Manage the $1M Threshold.
  • Charitable giving strategies to reduce taxable income. ESSB 6346 includes a $100,000 annual charitable deduction under §309. Strategies like donor-advised funds (DAFs), charitable remainder trusts (CRTs), qualified charitable distributions (QCDs), and gifts of appreciated stock can reduce your Washington taxable income while also maximizing the federal charitable deduction. For founders with large liquidity events, bunching multiple years of charitable giving into a single year can be particularly effective. See Charitable Giving Strategies to Reduce Your Washington Income Tax.
  • Proactive estate planning before 2028. Washington's estate tax (top rate 20%, exemption ~$3M) and the new 9.9% income tax interact in ways that make estate planning more urgent than ever. Tools like GRATs, ILITs, gifting programs, and credit shelter trusts need to be re-evaluated in light of both taxes simultaneously. For founders whose wealth is concentrated in illiquid private company stock, the combination of estate tax on death and income tax on liquidity events is a significant double exposure. See Estate Planning Before 2028: How Washington's Income Tax Changes the Calculus.
  • ING/NING/DING trusts: widely marketed, but they won't work here. Incomplete Non-Grantor (ING) trusts — including Nevada ING (NING) and Delaware ING (DING) variants — were aggressively marketed to Washington residents as a way to eliminate state income tax on investment income and capital gains. The core pitch: transfer assets to an out-of-state trust before a liquidity event, and the gain is taxed in the trust's state (Nevada or Delaware, both with no income tax) rather than Washington. The problem is that ESSB 6346 was written with anti-avoidance rules specifically designed to reach these structures. Washington will likely treat ING trust income as taxable to the Washington grantor regardless. These trusts carry significant legal risk, ongoing administrative cost, and IRS scrutiny — and should not be relied upon as a primary planning strategy under the new law. See ING Trusts Won't Save You from Washington's Income Tax. Here's What Might. for the full analysis and a discussion of what actually does work.
  • Monitor legislative developments actively. The tax landscape is not static. The QSBS add-back bills will likely return. The income tax rate could increase over time — Washington's history with new taxes strongly suggests it will. See Will Washington's Income Tax Rate Go Up? (History Says Yes). Work with advisors who are actively tracking Olympia, not just reactive to headlines.
  • Monitor legislative developments: The tax landscape is changing rapidly. Work with advisors who are actively monitoring Olympia and can adjust strategies in real time.

10a. The Pass-Through Entity Tax Election: Bypassing the SALT Cap

One of the most valuable — and most overlooked — planning tools for Washington pass-through business owners is the Pass-Through Entity (PTE) tax election under ESSB 6346.

Here's the core insight: the federal $10,000 SALT deduction cap applies to individuals. It does not apply to businesses. The PTE election allows an S-corp, LLC, or partnership to pay the Washington income tax at the entity level rather than passing it through to individual owners. Because the entity pays the tax, it is deducted as an ordinary business expense — outside the SALT cap entirely, and not subject to the $10,000 limitation.

For a founder or executive with $2 million in pass-through income, the 9.9% Washington tax would otherwise cost roughly $99,000 in state tax with zero federal deduction benefit (assuming they're already at the SALT cap). With a PTE election, that same $99,000 flows through as a business deduction, generating a federal tax offset at whatever marginal rate applies — potentially 37% for high earners. That's roughly $36,000 in federal tax savings on top of the state tax obligation.

The catch: Washington's Department of Revenue has not yet issued regulations or administrative guidance implementing the PTE election mechanics under ESSB 6346. Until that guidance arrives, the practical details — how to make the election, whether it applies to the capital gains tax as well, and how K-1 income is sourced — remain unresolved. Watch this space closely as 2028 approaches.

For a detailed breakdown of how the election works and its interaction with the B&O tax, see: The Pass-Through Entity Tax Election, Explained.

11. Will the Income Tax Survive a Court Challenge?

The constitutional challenge is no longer hypothetical — it’s underway.

On April 9, 2026, the Citizen Action Defense Fund (CADF) filed suit against ESSB 6346 in Klickitat County Superior Court. The legal team includes former Washington Attorney General Rob McKenna and former Washington Supreme Court Justice Phil Talmadge. The National Federation of Independent Business (NFIB) has also joined the challenge.

The core constitutional argument: income is property under Washington law, and the state constitution requires property taxes to be applied uniformly and cannot exceed a rate of 1%. This makes a graduated income tax unconstitutional — the same argument that prevailed in Culliton v. Chase (1933). The challengers argue that ESSB 6346 directly taxes “the receipt of income,” making the excise-tax framing used to save the capital gains tax much harder to sustain here.

Separately, Let's Go Washington founder Brian Heywood challenged the legislature's use of a "necessity clause" to shield ESSB 6346 from a voter referendum, taking the case directly to the Washington Supreme Court. On May 4, 2026, the Court issued a unanimous per curiam order in Heywood v. Hobbs, No. 105220-1, denying the petitioners' request for a writ of mandamus. The Court held that ESSB 6346 falls within the constitutional exception for laws "necessary for the support of the state government" and is therefore not subject to referendum. The order expressly addressed only referendum eligibility, not the constitutionality of the tax itself.

Let's Go Washington has since pivoted to an initiative campaign. Unlike a referendum, a citizen initiative goes directly to voters regardless of the necessity clause. The group has filed eleven Initiatives to the People (IP26-031, -045, -126, -202, -610, -703, -783, -852, -889, -913, and -986), each titled "Income Tax Repeal." The Attorney General issued ballot titles on May 7, 2026, and the filings are currently in the 5-day appellate window before final petition sheets can be printed. To qualify one of the IP filings for the November 2026 general election ballot, the campaign must submit 308,911 valid signatures (the Secretary of State recommends a cushion of roughly 390,000 submitted signatures to account for invalid ones) by July 2, 2026 at 5:00 p.m. An Initiative to the Legislature (December 31, 2026 deadline) would instead route the proposal to the 2027 legislature first; if lawmakers reject it or take no action, it would appear on the November 2027 ballot.

There are now three scenarios that could affect whether the tax takes effect in 2028: the CADF lawsuit succeeds and a court strikes down ESSB 6346 before 2028; the initiative qualifies and voters repeal it via the November 2026 ballot or legislative referral in 2027; or neither succeeds and the tax takes effect January 1, 2028 as written. Founders should not wait on any of these outcomes before planning. The prudent approach is to plan for the tax as written while preserving optionality if the law is changed or struck down. Work with counsel to document the basis for any refund position before filing.

For the full story on the lawsuit, see The First Lawsuit Against Washington’s Income Tax Is Being Filed Today and Why the Lawsuit Against Washington’s Income Tax Has a Real Chance. For the referendum case, see The Washington Supreme Court Just Fast-Tracked the Income Tax Referendum Case. For the deeper constitutional analysis, see Why Washington’s New Millionaire Tax Faces a Serious Constitutional Problem.

12. Legislative Timeline & Key Dates

Here’s a timeline of key tax developments:

  • 2021: Seattle JumpStart payroll tax implemented.
  • 2023: Capital gains tax takes effect; WA Cares payroll tax delayed to 2026.
  • 2024: Legislature proposes 7% income tax above $1 million; QSBS add-back bills introduced.
  • 2025: Capital gains tax expanded; QSBS exclusion remains intact (for now).
  • March 12, 2026: ESSB 6346 (millionaires’ tax) passes the legislature 51-46.
  • March 30, 2026: Governor Ferguson signs ESSB 6346 into law. SB 6229 and HB 2292 (QSBS add-back bills) die in committee.
  • April 9, 2026: CADF files the first constitutional challenge to ESSB 6346 (Klickitat County Superior Court), led by former AG Rob McKenna and former Justice Phil Talmadge. NFIB joins the suit.
  • April 10, 2026: AG response due in the WA Supreme Court referendum case (Let’s Go Washington v. Secretary of State).
  • April 14, 2026: Let’s Go Washington reply due in the referendum case.
  • April 30, 2026: WA Supreme Court en banc conference on the referendum petition.
  • May 4, 2026: Washington Supreme Court issues a unanimous per curiam order in Heywood v. Hobbs, No. 105220-1, denying the petitioners' request for a writ of mandamus. The Court holds that ESSB 6346 falls within the constitutional exception for laws "necessary for the support of the state government" and is not subject to referendum. The order addresses only referendum eligibility, not the underlying constitutionality of the tax.
  • May 7, 2026: Attorney General issues ballot titles for eleven Let's Go Washington Initiatives to the People (IP26-031, -045, -126, -202, -610, -703, -783, -852, -889, -913, and -986), each titled "Income Tax Repeal." 5-day appellate window for ballot-title challenges begins.
  • July 2, 2026 (5:00 p.m.): Statutory deadline for Let's Go Washington to submit signatures on an Initiative to the People to qualify for the November 2026 general election ballot. The signature threshold is 308,911 valid signatures; the Secretary of State recommends submitting roughly 390,000 to account for invalid ones. (An Initiative to the Legislature route would instead have a December 31, 2026 deadline and would go to the 2027 legislature before voters.)
  • July 1, 2026: WA Cares payroll tax implementation date.
  • January 1, 2028: ESSB 6346 income tax takes effect (unless struck down or repealed).

Key dates to watch:

  • Supreme Court referendum ruling: Decided May 4, 2026 in Heywood v. Hobbs, No. 105220-1 (unanimous per curiam order) — the Court upheld the necessity clause and blocked the referendum. The new path to repeal is via the Let's Go Washington initiative campaign (eleven active IP26 filings; July 2, 2026 signature deadline to reach the November 2026 ballot).
  • Constitutional challenge timeline: The CADF lawsuit could take 12–18 months to reach the WA Supreme Court. Expect a ruling in early-to-mid 2027.
  • Election years: Changes in the legislature could shift the likelihood of tax proposals passing.

Need help assessing how Washington tax developments could affect your company, equity, or liquidity planning? Book a call to discuss your situation. Also see: Washington State Taxes Guide | Services

Will Washington’s Income Tax Rate Go Up? (History Says Yes)

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For a comprehensive planning guide, see the Washington State Tax Planning Guide for High Earners ($49.99).

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