Moving from Montreal to Seattle: Taxes, AI, and the Departure Tax

Montreal to Seattle runs on three overlapping talent pipelines rather than one generic move. Artificial intelligence researchers trained at Mila and scattered from the old Element AI team feed into Seattle’s AI and cloud scene. Game developers out of Ubisoft Montreal and the city’s broader studio cluster line up naturally with the Seattle-area studio and gaming ecosystem. Aerospace engineers from Bombardier and its supplier network have an obvious landing spot at Boeing. All three converge on Amazon, Microsoft, Boeing, and a startup scene that’s absorbed a steady stream of AI talent since the Mila years. The tax mechanics underneath run through three separate authorities before Washington enters the picture at all.

How different are the two tax systems?

The income tax disappearing is the headline, but sales tax, property tax, and the capital gains excise round out the real comparison.

Tax	Montreal / Quebec	Seattle / Washington
Personal income tax	Combined federal + Quebec top rate ~53.31%	None
Capital gains	50%/66.67% inclusion rate, taxed as income	7% excise above $270,000/year on long-term gains
Sales tax	QST 9.975% + GST 5%, ~14.975% combined	~10.25% combined state and local in Seattle
Property tax	Varies by borough, generally under 1%	King County averages close to 1% of assessed value
Separate tax authority	Yes, Revenu Québec	No, one state Department of Revenue
Estate tax	None provincially	State estate tax above $2.193 million

Why does this specific corridor exist?

Three pipelines drive it, and none of them are finance-led. AI: Mila’s research output and the Element AI alumni network built a talent pool that Amazon, Microsoft, and a wave of Seattle AI startups have been actively recruiting from for years. Gaming: Ubisoft Montreal is one of the largest studios in the world, and Seattle carries its own dense studio cluster alongside Nintendo of America and Valve nearby. Aerospace: Bombardier’s Montreal supply base sends engineers directly into Boeing’s Everett and Renton operations.

What happens to my Quebec tax bill on the way out?

Leaving Quebec triggers the same departure tax as any other exit: a deemed disposition of worldwide property at fair market value on the departure date, reported on the final TP-1. Unvested equity, RSUs already granted, and a non-registered brokerage account with real gains all get caught here, not later. Quebec’s provincial bracket tops out at 25.75% on income over roughly $126,000, stacked on the federal brackets to reach that ~53.31% combined figure.

Which three tax authorities apply in the move year?

The CRA, Revenu Québec, and the IRS, and that’s before Washington is even in the picture, since Washington has no income tax return to file at all. The final TP-1 goes to Revenu Québec, covering worldwide income to the departure date. The final T1 goes to the CRA, covering the same period federally. The IRS then gets a US return, dual-status or full-year under the first-year election. Three filings from one move, and none of them are optional.

What replaces my T4 and T5 on the way out?

Relevé slips. Quebec issues its own for the provincial return, the Relevé 1 for employment income alongside the federal T4, and the Relevé 3 for investment income alongside the T5. A partial-year Montreal employer, common for anyone leaving mid-project at a studio or a lab, issues the Relevé 1 on its own timeline, often weeks after the T4. The Quebec abatement, a 16.5% reduction of basic federal tax, has to be prorated to the months of actual Quebec residency in a departure year.

Does RAMQ coverage end the day I leave?

No. RAMQ coverage runs for the balance of the month you leave plus roughly three more months, a tail most departing Quebecers don’t budget for. After that window closes, you need Washington-side coverage, and Amazon, Microsoft, and Boeing all offer employer plans from day one, but a gap can still open if the move date and the plan start date don’t line up.

How does the capital gains excise catch tech equity?

Washington’s excise tax applies to the gain on sale, not the value at vesting, so it only bites if shares are held past vesting and appreciate before sale. Sell-to-cover at vest generally avoids it. Holding a concentrated position through an AI-sector run-up, then selling, is exactly where the $270,000 threshold gets crossed.

What changes on everyday cost of living?

Sales tax drops meaningfully, from Quebec’s combined QST-and-GST rate near 14.975% to roughly 10.25% in Seattle. Property tax runs the other way: King County averages close to 1% of assessed value, and Seattle-area home values sit well above most Montreal boroughs, so the dollar amount often lands much higher even where the rate looks comparable on paper.

Does Washington have its own estate tax?

Yes, and it’s a real change from Quebec, which has no separate estate or inheritance tax at all. Washington’s state estate tax applies above a $2.193 million exemption, well below the federal exemption, with rates running up to 20%. A Seattle-area home plus retirement accounts and a concentrated equity position can cross that line faster than people expect, particularly for anyone who settles permanently rather than treating the move as temporary.

Where do people actually end up living?

AI and cloud arrivals cluster around South Lake Union and Seattle proper, close to Amazon’s core campus, or Bellevue and Redmond near Microsoft. Aerospace arrivals from Bombardier’s pipeline tend to land in Everett, near Boeing’s widebody plant, or Renton, near the 737 line. None of this changes the state-level tax picture, since Washington has no city income tax anywhere, but King versus Snohomish County property tax rates do vary by a meaningful margin.

What should I do before the move?

Close the Quebec side first: confirm the departure date, gather both the T4/T1 and Relevé/TP-1 slip sets, deregister for QST if applicable, and prorate the Quebec abatement to the actual months of residency. Then map any RSU or equity sale timing against the $270,000 excise threshold before the shares hit your account, and confirm the RAMQ tail doesn’t leave a coverage gap before the Washington-side plan starts.

• Moving from Quebec to Washington State, the province-level version of this corridor
• Moving from Quebec to the US, the full Quebec departure mechanics
• Moving from Montreal to New York, the finance and gaming corridor from the same city
• Moving from Montreal to San Francisco, the sibling AI corridor
• Moving from Montreal to Boston, the research and pharma corridor
• Moving from Montreal to Chicago, the flat-tax Midwest corridor
• Moving from Montreal to Austin, the AI and tech corridor into Texas
• Moving from Montreal to Los Angeles, the VFX and entertainment corridor
• Moving from Montreal to Miami, the no-state-income-tax comparison
• Moving from Montreal to Washington DC, the international organizations corridor
• Moving from Montreal to Denver, the AI and outdoor corridor
• Vancouver to Seattle, the same destination from BC’s tech corridor
• Toronto to Seattle, the two-authority version from Ontario
• Calgary to Seattle, the energy-to-tech sibling corridor
• Canada to Washington, the generic version from any province
• The Canadian departure tax and its forms
• The leaving-Canada checklist
• RRSP and TFSA moving to the US
• The US-Canada tax treaty explained
• Your first US tax return as a new immigrant
• Provincial health insurance and leaving Canada, the RAMQ tail mechanics
• State income tax for cross-border filers
• Montreal to Portland, the gaming corridor into Oregon
• Montreal to Minneapolis, the corporate HQ corridor into Minnesota

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.