Canadian Snowbirds in 2026: The 30-Day Registration Rule and the Tax Trap Behind It

There are roughly a million Canadians who spend a meaningful part of every winter in the United States. Most of them believe two things that are not quite true: that the "six month rule" is what governs their stay, and that immigration compliance and tax compliance are the same problem.

Neither has ever been correct. Since 2025, when a registration requirement began applying to Canadians staying 30 days or more, the gap between what snowbirds believe and what the rules say has become considerably more expensive.

This guide covers both halves of the problem: the immigration requirement to register, and the entirely separate tax question of whether you have become a US resident for tax purposes. They are governed by different agencies, different thresholds, and different forms, and satisfying one tells you nothing about the other.

Part one: the 30-day registration requirement

Since 2025, Canadian visitors aged 14 and over who are not issued an electronic Form I-94 and who stay in the United States for 30 days or longer must register with US Citizenship and Immigration Services.

Who this actually affects

The distinction that determines whether you need to act is how you entered.

Arriving by air. Canadians flying into the US are automatically issued an electronic I-94. If you have an I-94, you are already registered, and no further action is required.

Arriving by land. Canadians crossing at a land port of entry frequently are not issued an I-94. If you were not, and you are staying 30 days or more, you must register separately.

This is precisely backwards from most people's intuition. The snowbird who drives to Florida every year, who feels like the most established and routine of travellers, is the one caught by the requirement. The one who flies is already covered.

How and when to register

Registration is made using Form G-325R, filed online with USCIS. It must be completed before the 30-day period expires, though registering within a few days of arrival is the sensible course rather than waiting.

The form asks for biographical details and address information in the United States. There is no fee for the registration itself.

Why this is not the tax rule

Registration is an immigration formality administered by USCIS. It does not grant you any additional time in the US. It does not extend the period you are admitted for. And, critically, it provides no protection whatsoever from becoming a US tax resident.

Being properly registered and being taxed as a US resident are entirely compatible states. Many snowbirds will be both.

Part two: the Substantial Presence Test

This is the rule that costs money, and the one that most snowbirds have never fully worked through.

Under Internal Revenue Code section 7701(b), a foreign national becomes a US resident for tax purposes if they meet the Substantial Presence Test. Meeting it means the United States asserts the right to tax your worldwide income, and to require the associated reporting on foreign accounts and assets.

The formula

You meet the test if both conditions hold:

• You were present in the US for at least 31 days during the current year, and
• The weighted total across three years reaches 183 days, calculated as:

all days this year + one third of last year's days + one sixth of the year before

The weighting is what catches people. A snowbird who spends four months in Florida every year is not spending 183 days annually. They are spending roughly 120. But run the formula:

• Current year: 120 days = 120
• Prior year: 120 ÷ 3 = 40
• Year before: 120 ÷ 6 = 20
• Total: 180

That is under 183, but only just. Add two extra weeks in any year, or a summer visit, and the same person crosses the line without a single year that looked unusual.

This is why the folk wisdom of "under six months and you're fine" is dangerous. Six months a year, sustained, blows through the test comfortably. Even four months a year sits within a fortnight of it.

What being a US tax resident actually means

If you meet the test and no exception applies:

• You are taxed on worldwide income, not just US-source income.
• You may need to file FinCEN Form 114 (FBAR) for foreign financial accounts exceeding the threshold, which for a typical Canadian means chequing accounts, RRSPs, TFSAs and investment accounts.
• You may need to file Form 8938 for specified foreign financial assets.
• Canadian registered accounts become complicated. TFSAs in particular are not recognised as tax-sheltered by the IRS and can create reporting obligations that substantially outweigh their benefit.

The penalties for missed foreign account reporting are severe and are assessed per account per year. This is the part of the snowbird problem that turns an administrative oversight into a genuinely large number.

The escape hatch: the Closer Connection Exception

If you meet the Substantial Presence Test but spent fewer than 183 days in the US in the current year, you may still be treated as a non-resident if you can show you have a closer connection to another country.

You claim it by filing Form 8840, the Closer Connection Exception Statement, generally by the due date for a US return.

The factors considered include where your permanent home is, where your family lives, where your personal belongings are, where you are registered to vote, where your driving licence is issued, where your banking is conducted, and which country you list as your residence on official forms.

Three things about Form 8840 are worth being blunt about.

It is not automatic. The exception must be claimed. Meeting the criteria and not filing the form leaves you, on the IRS's view, a US tax resident.

It fails if you hit 183 days in the current year alone. No matter how strong your connection to Canada, the exception is unavailable if you were physically present for 183 days or more this year.

It requires you to know your day count precisely. The form asks for the number of days present in the US in each of the last three years. Guessing on a federal form is not a good position, and this is a form specifically designed to be checked against border records.

There is a separate route under the Canada–US tax treaty, using tie-breaker rules to establish residence in one country where both assert it. That is filed differently, on Form 8833, and is a more involved position. Anyone in genuine doubt should take advice rather than choose between forms by guesswork.

How the two rules interact

Here is where snowbirds most often go wrong. The immigration rule and the tax rule use different thresholds, different agencies, and different forms, and compliance with either says nothing about the other.

	Immigration	Tax
Trigger	30 days without an I-94	Weighted 183 days over 3 years
Agency	USCIS	IRS
Form	G-325R	8840 (or 8833)
Consequence of ignoring	Status and future entry problems	Worldwide taxation and foreign account penalties

A snowbird can be perfectly registered and squarely a US tax resident. A snowbird can be under every tax threshold and in violation of the registration requirement. The two questions must be answered separately.

There is also an enforcement dimension that did not previously exist in the same form. US Customs and Border Protection holds entry and exit records, and can see when a traveller stayed beyond 30 days, was not issued an I-94, and never filed a G-325R. Day counts declared on tax forms sit alongside a border record that the government already has.

Common questions

Is there a "six month rule"?

Not as commonly understood. Canadians are typically admitted to the US for up to six months at a time, which is an immigration permission. It says nothing about tax residency, and the Substantial Presence Test can be met on considerably fewer than six months a year when sustained across three years.

Does a day trip count?

For the Substantial Presence Test, any part of a day physically present in the US counts as a full day. A morning of shopping across the border is a day. Over a border-city lifetime, these accumulate significantly.

There are narrow exclusions, including days you were unable to leave due to a medical condition that arose in the US, and certain days for commuters from Canada or Mexico who regularly commute for work. These are specific and worth checking rather than assuming.

I have registered under the 30-day rule. Am I now fine?

For immigration purposes, if you registered correctly and are within your admitted period, yes. For tax purposes, registration is irrelevant. It neither triggers nor prevents tax residency, and filing G-325R does not substitute for Form 8840.

What if I have been meeting the test for years without filing anything?

Take professional advice promptly. There are established procedures for coming into compliance, and outcomes are consistently better for taxpayers who approach the IRS than for those the IRS approaches. The foreign account reporting penalties are the exposure that matters most.

Do days in the US as a Canadian citizen count differently?

No. The Substantial Presence Test is nationality-neutral. Canadian citizenship neither exempts you nor changes the arithmetic. What Canadian residence gives you is a strong basis for the Closer Connection Exception, but you have to claim it.

Does time in Canada reduce my US day count?

Only in the sense that a day in Canada is not a day in the US. There is no netting. The test counts US days, full stop.

Practical guidance

Count every US day, including partial ones. Arrival and departure days both count. Day trips count. If you cross a land border regularly, this is the difference between an accurate return and a guess.

Run the three-year formula annually, before year end. By the time you are filing, the year is closed and nothing can be adjusted. Running it in October leaves you the option of shortening a stay.

File Form 8840 if you rely on the closer connection exception. Every year. It is not a standing election.

Register under the 30-day rule if you drove. Check whether you received an electronic I-94. If you crossed by land and stayed 30 days or more, assume you did not, and file G-325R.

Keep a contemporaneous day log. Both forms ask for day counts, and both are checkable against CBP records. Reconstructing from memory produces discrepancies, and discrepancies invite examination.

Worked examples

The four-month regular

Bill has spent January through April in Arizona every year for a decade. Roughly 120 days a year.

• Current year: 120
• Prior year: 120 ÷ 3 = 40
• Year before: 120 ÷ 6 = 20
• Total: 180

He is three days under the threshold, every year, in perpetuity. He has never known this. One year his daughter's wedding adds a week in June and the total reaches 187. He meets the Substantial Presence Test and, absent a Form 8840, is a US tax resident with worldwide income exposure and foreign account reporting on his RRSP and TFSA.

The trip that broke it was seven days long.

The five-month snowbird

Diane spends late October to late March in Florida, about 150 days.

• Current year: 150
• Prior: 50
• Year before: 25
• Total: 225

She meets the test comfortably and has for years. Because she is under 183 days in the current year, the Closer Connection Exception is available to her, but only if she files Form 8840. Many people in her position have never filed it, on the understanding that being Canadian is sufficient. It is not.

The border commuter

Raj lives in Windsor and works in Detroit, crossing most weekdays.

At roughly 240 crossings a year, each counting as a full day present, his raw count is enormous. There is a specific exclusion for regular commuters from Canada or Mexico, which is precisely why it exists, but it must be applied correctly and the days excluded must be genuine commuting days. Days he stays over, or crosses for leisure, do not qualify.

This is the group for whom accurate daily records matter most, because the difference between a commuting day and a personal day is invisible in a raw border record.

Florida, Arizona and state-level questions

Snowbirds often assume that state tax follows the same rules as federal. It does not, and the interaction produces its own traps.

Florida, Texas, Nevada and Washington have no state income tax, which is much of their appeal. A snowbird spending winters there has no state filing obligation from the presence alone.

Other states differ. Arizona, California and others do impose income tax, and their residency rules are separate from both the federal Substantial Presence Test and from Canadian rules. Spending six months in California is a materially different proposition from spending six months in Florida.

Property ownership complicates things. Owning a home in a state can create filing obligations on rental income, and in some states affects residency analysis. It also creates US estate tax exposure, which catches Canadians by surprise because the Canada-US treaty relief is not automatic and requires filing.

The Canada side of the ledger

Meeting the US Substantial Presence Test does not, by itself, end Canadian tax residency. Canada determines residency primarily on residential ties: a home available, a spouse or dependants in Canada, and secondary ties like driving licences, health coverage and bank accounts.

The likely outcome for a typical snowbird is that both countries consider them resident. The Canada-US treaty then applies tie-breaker rules, in order: permanent home available, centre of vital interests, habitual abode, and citizenship.

Most snowbirds resolve as Canadian residents under these rules, which is the correct and expected outcome. But resolving it requires taking a treaty position and filing accordingly, not simply assuming it.

A specific warning: provincial health coverage generally requires a minimum physical presence in the province, commonly around five to seven months depending on the province. It is entirely possible to satisfy the US rules, satisfy the treaty, and still lose provincial health coverage by being away too long. That is a third rulebook, with a third threshold, and it is the one that hurts immediately rather than at filing time.

Frequently asked questions

Do I have to file a US tax return if I meet the Substantial Presence Test?

If you meet it and do not qualify for an exception, you are treated as a US tax resident and are generally required to file Form 1040 reporting worldwide income. The Closer Connection Exception, claimed on Form 8840, is the usual route out, and it requires the filing. Failing to file the form is what converts a manageable situation into an expensive one.

What is the deadline for Form 8840?

It is generally due by the due date of a US income tax return, mid-June for those not otherwise required to file. Late filing can result in the exception being denied, so treating it as an annual June task is the safe approach.

Does the day I fly down count?

Yes. Any day on which you are physically present in the United States at any point counts as a full day, including partial days at either end of a trip.

Do days in transit count?

There is a narrow exclusion for individuals in transit between two foreign points who are present in the US for less than 24 hours. A connection through Chicago on the way to Europe generally does not count. A stopover with an overnight generally does.

What about medical days?

Days on which you were unable to leave the United States because of a medical condition that arose while you were there can be excluded, claimed on Form 8843. The condition must have arisen while present in the US, so a pre-existing condition that worsened does not qualify on the same basis.

Does owning US property make me a US tax resident?

Not by itself. Residency turns on presence and the tests above. But property ownership creates its own obligations, including filing on rental income and potential US estate tax exposure, which is separate from income tax residency and frequently overlooked.

If I file Form 8840, does Canada need to know?

Form 8840 is a US filing. Your Canadian return is unaffected by it directly, but the underlying facts matter to both, and inconsistent positions across two returns are the sort of thing that surfaces under information sharing between the CRA and the IRS.

Does the new registration requirement affect my tax position?

Not directly. The G-325R registration is an immigration compliance matter under existing law. Its practical effect on tax is that it creates another government record of exactly how long you were in the country, which makes accurate day counting more important rather than less.

Where iReside fits

The single most useful thing a snowbird can have is an accurate, dated record of which side of the border they were on. Both halves of this problem reduce to that.

iReside records your location by day automatically. For snowbirds specifically:

It counts US days the way the IRS does. Partial days as whole days, arrival and departure both counted, across the three-year weighted window rather than a single calendar year.

It warns you before the threshold, not after. The Substantial Presence Test is only avoidable while the year is still open. An alert in November is worth something; a calculation in April is history.

It produces the numbers the forms ask for. Form 8840 wants your day counts for three consecutive years. Reading them off a record beats reconstructing them from memory, and it is more defensible if CBP data is compared against your return.

To check where you stand now, our free Substantial Presence Test calculator runs the three-year weighted formula, handles the 31-day minimum, and flags whether the Closer Connection Exception remains available. It runs entirely in your browser.

Canadians also managing a permanent residence obligation on the Canadian side should read our guide to the 730-day rule, since US days and absences from Canada are the same days counted twice, for two different governments, with two different consequences.

The bottom line

Snowbirding has always involved two independent rulebooks. What changed is that both are now enforced against a border record the government already holds, and one of them acquired a registration requirement that specifically catches people who drive.

The 30-day rule is administrative and easy to satisfy once you know it applies to you. The Substantial Presence Test is the one that can reach your worldwide income and your Canadian accounts, and it is met by day counts that feel entirely ordinary.

Both come down to the same question, asked in two places: exactly how many days were you in the United States? It is worth being able to answer that precisely, before somebody else does.

Sources

• Alien Registration Requirement — USCIS — the 30-day threshold, and that it applies per trip.
• Form G-325R, Biographic Information (Registration) — USCIS
• Substantial presence test — IRS — the 183-day weighted three-year calculation.
• About Form 8840, Closer Connection Exception Statement for Aliens — IRS