Florida's snowbird population is largely Canadian. Many of them spend six months in Florida every year, never thinking about the IRS. They probably should: cross 183 days under the IRS's three-year rolling formula and you become a US tax resident — exposed to US tax on worldwide income.
The formula
The substantial-presence test (SPT) is set out in IRC section 7701(b)(3). It counts:
- All days physically present in the US in the current year, PLUS
- One-third of days physically present in the prior year, PLUS
- One-sixth of days physically present in the year before that
If the total is 183 or more — and you were present at least 31 days in the current year — the SPT is met and the IRS treats you as a US tax resident for the current year.
The math for a typical snowbird
A snowbird who spends 150 days in Florida every year reaches: 150 + 50 + 25 = 225. That's well over the 183 threshold. Even a moderate snowbird at 130 days per year hits 130 + 43 + 22 = 195 — still over.
The SPT, in other words, catches almost every meaningful snowbird pattern unless something else cuts it off.
The closer-connection statement
The first counter-measure is Form 8840, the Closer Connection Exception Statement. It is available to a non-US-citizen who: (1) was present in the US for fewer than 183 days in the current year; (2) had a tax home in a foreign country for the current year; and (3) had a closer connection to that foreign country than to the US during the current year.
"Closer connection" is a multi-factor test built on the location of: permanent home, family, vehicles, social ties (churches, clubs), banks, voter registration, driver's licence, business activities. A Canadian snowbird who keeps a Canadian permanent home, has provincial healthcare, holds an Ontario driver's licence, and votes federally in Canada almost always wins on closer-connection — but only if Form 8840 is filed on time.
Form 8840 must be filed by the due date of the US return (June 15 for non-residents). Late forms invite rejection of the closer-connection claim even where the facts support it. Filing every year is mechanical and cheap.
What if you exceed 183 days in the current year?
If you cross 183 days in the current year alone, Form 8840 is unavailable — the closer-connection exception is unavailable. The next defence is the Canada-US treaty's Article IV residency tie-breaker, which resolves dual-residency conflicts by reference to (in order):
- Permanent home available in each state — if only one state has a permanent home, that state wins.
- Centre of vital interests — economic and personal ties.
- Habitual abode — where the individual habitually lives.
- Citizenship — last tie-breaker.
To claim treaty residency, the individual files Form 1040-NR with Form 8833 (Treaty-Based Return Position Disclosure). The position is annual.
What you cannot avoid: estate-tax exposure
Even if the SPT is defeated and you file no US return, US estate tax can still apply at death on US-situs assets you own — the Florida condo, the US-corporation shares, the tangible personalty kept at the snowbird residence. The Canada-US treaty's prorated unified credit provides relief but not necessarily complete elimination. Snowbirds with substantial US-situs holdings should review the estate-tax exposure separately from the income-tax analysis. See our US Estate Tax for Canadians page for the framework.
The takeaway
For most Canadian snowbirds, the answer is simple: file Form 8840 every year, on time, with accurate closer-connection facts. The form takes 15 minutes to prepare and removes any meaningful US income-tax exposure. The hardest cases are snowbirds who have already started behaving like US residents — long stays, Florida driver's licences, Florida vehicle registrations — and need treaty positions to undo the optics.