Moving from Canada to Colorado: State Tax, TABOR Refunds, and Cross-Border Planning

Colorado charges a flat 4.4% state income tax on all taxable income, which is lower than every Canadian province’s top marginal rate and lower than most US states with an income tax. It also has something no other state offers: a mandatory refund under the Taxpayer’s Bill of Rights (TABOR) when state revenue exceeds a constitutional cap, paid as a tax credit on your Colorado return or as a direct check. For Canadians relocating to Denver, Boulder, Colorado Springs, or the mountain towns, the state tax layer is straightforward compared to destinations like California or New York, but the federal cross-border obligations are identical regardless of state.

How does Colorado’s flat tax compare to provinces?

Colorado’s 4.4% flat rate applies to all taxable income with no brackets. Here’s how it compares to the provincial layer you’re leaving:

Province	Top marginal provincial rate	Income where it kicks in
Ontario	~20.5% (including surtax)	$220,000+
BC	20.5%	$252,752+
Alberta	15%	$355,845+
Quebec	25.75%	$126,000+
Colorado	4.4% (flat)	All income

The difference is dramatic at higher incomes. On $300,000 of employment income, the provincial tax in Ontario would be roughly $35,000 to $40,000, while Colorado’s flat rate produces about $13,200. The federal rates on both sides are their own comparison, but the provincial-to-state shift is where the move shows the largest immediate tax reduction for most people.

What is the TABOR refund and do I qualify?

The Taxpayer’s Bill of Rights (TABOR) is a constitutional provision unique to Colorado. It caps the state’s annual revenue growth and requires any excess revenue to be refunded to taxpayers. In practice, this means that in years when Colorado collects more tax than the cap allows, every resident who files a Colorado return receives a refund.

For the 2024 tax year, the refund was $800 per individual filer and $1,600 for married filing jointly. It’s claimed as a credit on the Colorado return, not as a separate check (though the state has used direct payments in some years).

To qualify, you need to be a Colorado resident for the full tax year (or for the portion of the year you lived there, prorated) and file a Colorado income tax return. A Canadian who arrives mid-year would receive a prorated amount. The refund is not taxable for Colorado purposes, but it may be taxable on your federal return under the tax benefit rule if you itemized deductions and claimed state taxes paid in the prior year.

How does Colorado treat the RRSP?

Colorado starts its income calculation from federal taxable income. Because the RRSP treaty deferral under Article XVIII keeps the annual growth out of federal taxable income (assuming you’ve made or are deemed to have made the election), Colorado doesn’t add it back. The practical result is the same as having no state tax on RRSP growth while the plan is deferred.

When you take RRSP withdrawals, they’re included in federal taxable income and flow through to Colorado’s taxable income at the flat 4.4% rate. This is simpler than states like California, which ignores the treaty deferral and taxes RRSP growth annually.

The TFSA is taxable at the federal level (it’s a foreign trust for US purposes), and that federal income flows through to Colorado. The recommendation is still to collapse the TFSA before leaving Canada to avoid ongoing Form 3520/3520-A reporting.

What happens on the Canadian side when I leave?

The standard departure sequence:

• Deemed disposition of worldwide assets at fair market value (except Canadian real property, pension plans, and certain other excluded property)
• Final Canadian return from January 1 to the departure date, with all income and gains up to that date
• Provincial tax at the rates of the province you’re leaving (based on your province of residence on departure day)
• T1161 and T1243 if you own property worth more than $25,000 at departure
• RRSP/RRIF left in place or collapsed, depending on the plan (the RRSP stays open and the treaty deferral applies; the TFSA should be closed)
• CRA notification of your new address and non-resident status
• NR73 is optional but can confirm your departure date for the record

What about Colorado’s other taxes?

Beyond the flat income tax:

Sales tax. Colorado’s state sales tax is 2.9%, but local jurisdictions add their own layers (city, county, special districts). In Denver, the combined rate is about 8.81%. In Boulder, it’s about 8.845%. This is comparable to or higher than the HST rate in Ontario (13%) or BC (5% GST + 7% PST on taxable goods), though the taxable base differs. Colorado exempts most groceries from state sales tax (though some local jurisdictions still tax them).

Property tax. Colorado property taxes are moderate by US standards. The assessment rate for residential property is 6.7% of actual value (2025), and the mill levy varies by district. The effective rate on a $600,000 home in the Denver metro area is roughly 0.5% to 0.7%, which is lower than most Canadian municipalities.

Estate tax. Colorado has no state estate tax or inheritance tax. The only estate tax exposure is the federal estate tax, which applies to estates above $13.61 million for US citizens and residents (or the much lower $60,000 threshold for non-citizens without treaty relief). This is simpler than states like Washington, which imposes its own estate tax above $2.193 million.

What about Colorado’s residency rules?

Colorado defines a resident as anyone who is domiciled in Colorado or who maintains a permanent place of abode in Colorado and spends more than six months (183 days) in the state during the tax year. For a Canadian moving permanently, you become a Colorado resident on the day you arrive with the intent to stay. Your first-year return is a part-year return covering the period from arrival through December 31, with Colorado income taxed at the flat 4.4% rate.

If you maintain a home in Canada during the transition, Colorado’s “permanent place of abode” rule is based on where you’re domiciled, not just where you have a house. But having homes in both places during a transition year can create questions about residency timing on both sides. The Canadian residency determination and the treaty tie-breaker resolve overlapping claims.

What if I’m self-employed or running a business?

Colorado follows the federal treatment of self-employment income, so Schedule C or S-corp distributions flow through to Colorado at the same 4.4% rate. There’s no separate business tax like Washington’s B&O tax. If you’re keeping a Canadian corporation while living in Colorado, the US federal reporting obligations (Form 5471, GILTI, Subpart F) apply, and the Canadian corporate income included on your US return flows through to Colorado.

Colorado also has a retail delivery fee ($0.29 per delivery in 2024) that applies to businesses making deliveries in the state, plus various industry-specific taxes and fees, but these don’t affect most cross-border movers unless they’re running an e-commerce or delivery business.

What should I do next?

The Canadian exit follows the standard checklist. On the Colorado side, the main planning items are timing the move to optimize the part-year split (Colorado’s low rate means you want more income falling into the Colorado period if possible), the TABOR refund eligibility, and the health insurance transition.

• Departure tax checklist, the full Canadian exit sequence
• RRSP and TFSA on a US move, federal treatment and reporting
• State income tax for cross-border filers, comparing Colorado to other states
• First US tax return after moving from Canada, the arrival-year mechanics
• Canada vs US tax rates, the full bracket comparison
• Treaty tie-breaker rules, resolving dual residency in the move year
• Moving from Canada to North Carolina, another low flat-rate corridor for comparison
• Moving from Canada to Massachusetts, a higher-rate flat-tax state with a millionaire’s surtax
• Moving from Canada to Utah, the neighboring flat-rate state with Silicon Slopes tech
• Moving from Canada to Wyoming, the no-income-tax neighbor to the north

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