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Washington State Taxes

Washington State Tax Policy for Startups

🚨 New — Published March 12, 2026
Washington's New Income Tax: What Founders, Investors, Athletes, and High Earners Need to Know
The Legislature has passed SB 6346 — a 9.9% tax on household income above $1 million. Our complete guide covers how it works, what it means for QSBS holders, the marriage penalty, the athlete and NIL angle, the constitutional fight ahead, and what to do before 2028.
Read the Full Guide →
  1. The Full Tax Stack: What Founders Are Actually Facing
  2. The Capital Gains Tax (Already Law)
  3. The Proposed Millionaire Income Tax
  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 first $250,000 of long-term capital gains is exempt. Gains between $250,000 and $1 million are taxed at 7%. Gains above $1 million are taxed at 9.9%.

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 (Passed Legislature; Awaiting Signature)

On March 12, 2026, the Washington legislature passed SB 6346, imposing a 9.9% tax on household income above $1 million. Gov. Bob Ferguson has said he will sign it. If signed, 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) — SB 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.

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 up to the Social Security wage base. Originally slated to begin in 2022, implementation was delayed until 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.

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) is 1.5% of gross receipts. 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 $30,000 (1.5% of $2m). 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 amount is $2.193 million for 2025, adjusted annually for inflation.

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.

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

Given this evolving landscape, founders should consider the following strategies:

  • Accelerate QSBS-eligible transactions: If you’re considering selling QSBS, doing so before any add-back rule passes could save you millions.
  • Diversify your residency: If possible, establish residency in a state with no income tax before a major liquidity event. This often requires more than just buying a second home; you must demonstrate that your primary domicile has shifted.
  • Engage in proactive estate planning: Use trusts, family limited partnerships, and other tools to minimize estate tax exposure.
  • Monitor legislative developments: The tax landscape is changing rapidly. Work with advisors who are actively monitoring Olympia and can adjust strategies in real time.

11. Will the Income Tax Survive a Court Challenge?

Washington's constitution explicitly prohibits a graduated income tax. The capital gains tax survived because the court classified it as an excise tax on the privilege of selling assets, not an income tax. SB 6346 uses the same excise framing, and its supporters believe the 2023 capital gains ruling clears the path.

Now that SB 6346 has passed the legislature, a court challenge is virtually certain. The outcome depends on whether the Washington Supreme Court accepts the excise framing for a broad-based income tax, and whether the flat-rate structure survives the uniformity analysis that blocked a graduated income tax in 1933.

Founders should assume the tax could take effect for at least a few years before a final ruling is reached. Plan for the possibility of paying the tax while also pursuing refund claims if the tax is struck down.

12. Legislative Timeline & Key Dates

Here’s a rough timeline of recent and proposed 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).
  • July 1, 2026: WA Cares payroll tax implementation date.
  • March 12, 2026: SB 6346 (millionaires' tax) passes the legislature 51-46; awaiting governor signature. SB 6229 and HB 2292 (QSBS add-back bills) die in committee.

Key dates to watch:

  • Legislative session (Jan–Apr): New bills can be introduced and advanced.
  • Election years: Changes in the legislature could shift the likelihood of tax proposals passing.
  • Court rulings: Any litigation over the income tax or QSBS add-back could take years to resolve.

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

Book a 20-Minute Intro Call →

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

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