Direct AnswerCanadian snowbirds who own a California home but split the year must track the IRS substantial presence test: at least 31 days in the current year and a weighted 183 days over three years can make you a US tax resident unless an exception (such as the closer-connection exception, via Form 8840) applies. The US-Canada income tax treaty (Article XVIII) governs cross-border pensions and allows deferral of US tax on RRSP/RRIF growth; the two countries also have a Social Security totalization agreement. California has its own residency tests. Brian handles the real estate; he is a REALTOR®, not a CPA - plan days and filings with a cross-border professional.
For Canadian snowbirds, the home purchase is the easy part - the day-counting is what needs care. Here's the framework before you talk to a cross-border CPA.
The substantial presence test
You may become a US tax resident if you're physically present in the US for:
at least 31 days in the current calendar year, AND
at least 183 days over three years, counted as: all days this year + 1/3 of last year's days + 1/6 of the prior year's days.
Many snowbirds stay under the line, or use the closer-connection exception (IRS Form 8840) to maintain Canadian tax residency despite significant US time - if they qualify. Treaty tie-breaker rules can also apply.
Pensions: Article XVIII
Article XVIII of the US-Canada treaty addresses cross-border pensions and lets a US person elect to defer US tax on income accruing inside an RRSP/RRIF until distribution. The two countries also have a Social Security totalization agreement. TFSAs, by contrast, are generally not recognized as tax-free by the IRS.
California residency is separate
California applies its own residency analysis, independent of the federal test. Owning a California home is one factor among many. If you intend to remain a Canadian resident, structure your time and ties deliberately - with professional guidance.
Owning property here does not by itself make you a US or California tax resident - but days and ties do. Coordinate the calendar with a cross-border CPA before you commit to a part-year pattern.
Important - please read: Brian Cooper is a licensed California REALTOR® (DRE# 01434286), not an immigration attorney, CPA, tax adviser, or financial adviser. The visa, tax-treaty, FIRPTA, mortgage, and currency information here is general and educational - confirm your own situation with a qualified cross-border immigration attorney and CPA before acting. Any lender or service-provider referral is disclosed under RESPA. Equal Housing Opportunity - service-area awareness only, never steering by national origin or any protected class.
