Which Tax Residency Rules Apply to You? State + Visa + Test Matrix
This routing guide explains tax residency rules by situation, matching your country, US state, and visa to the exact test and guide that applies to your case.
Which tax residency rules apply to you depends on three things: which country you spend time in, whether a US state can also claim you, and what visa or immigration status you hold. Most people are governed by two or three of these layers at once. Start by identifying your situation in the matrix below, then jump straight to the guide that covers your exact test, the 183-day rule, the US Substantial Presence Test, the UK Statutory Residence Test, a state domicile rule, or a treaty tie-breaker.
The three layers of residency that can apply at once
There is no single "tax residency rule." You can simultaneously be a tax resident of a country, a US state, and a treaty partner, each running its own test on its own calendar. Sorting your situation means working through these layers in order:
- Country layer: nearly every country uses some version of a 183-day rule or a domicile/center-of-life test to decide if it can tax your worldwide income.
- US federal layer: if you spend meaningful time in the United States on a visa or green card, the Substantial Presence Test applies on top of any state rule, and it overrides a simple day count.
- US state layer: US states run their own residency tests (statutory day count plus domicile) that are entirely separate from federal status. You can be a non-resident for federal purposes and still a resident of a state.
- Treaty layer: when two countries both claim you, a treaty tie-breaker decides which one wins, but only between treaty partners, and only for income the treaty covers.
The layers don't cancel each other out. Passing a treaty tie-breaker can stop a country taxing your worldwide income, but it usually does nothing to a US state, states generally ignore federal treaties. Work each layer separately.
Route 1: which country rule applies
Find the country you spend the most time in, then read the guide for its specific test. The threshold matters less than the counting period and what counts as a day, those vary everywhere.
| If you spend time in… | The test that applies | Read this |
|---|---|---|
| Most countries (default) | 183 days in the local tax year | The 183-day rule explained |
| Thailand, Indonesia, Vietnam, SE Asia | 180–183 days, often remittance-based | Vietnam expat residency |
| United Kingdom | Statutory Residence Test (sliding 16–183 days by ties) | UK SRT rule page |
| Ireland, Cyprus, Italy, Greece | 183 days + non-dom / remittance regimes | Ireland non-dom guide |
| Portugal, Spain, France, Germany | 183 days + center-of-vital-interests | 183-day rule |
| Low-tax hubs (Monaco, Andorra, Georgia tax residency rules">Georgia, UAE) | Residency ≠ automatic tax exemption | Golden visa ≠ tax residency |
If you're a frequent traveler rather than a settler, the question is usually "how many days can I stay before I'm taxed?", start with that guide and run your dates through the 183-day calculator.
Route 2: which US state rule applies
US states are the layer people most often miss. A state can tax you two ways: you're domiciled there (your true, fixed, permanent home), or you're a statutory resident, you keep a permanent place to live there and spend more than the state's day threshold (often 183 or 184 days). Either path is enough. Match your situation:
| Your situation | What the state looks at | Guide |
|---|---|---|
| Snowbird splitting summer/winter | Day count + permanent home in each state | Snowbird tracking guide |
| Moved mid-year | Part-year residency, allocation of income | Part-year residency |
| High-tax state, trying to leave | Domicile change + cutting ties | Establishing Florida domicile |
| Remote worker in a new state | Day-count safe harbors, employer nexus | Remote worker residency |
| Living near a state border | Reciprocity agreements between states | State reciprocity |
| New York / California audit risk | NY day-count rule; CA domicile + closer-connection review | New York residency rules |
New York's statutory-residency day count treats any part of a day in the state as a full day, even a brief stopover can count. California leans less on a fixed day count and more on domicile and a facts-and-circumstances "closer connection" review, looking at where your home, family, business, and "near and dear" belongings sit. In both, leaving a high-tax state is about cutting ties, not just counting days.
Not sure where to begin? Pick your state from the rule pages, or read the broader domicile-vs-statutory-resident breakdown to understand the two paths before you check the specific numbers.
Route 3: which visa or immigration rule applies
Your immigration status can change the test entirely, sometimes it makes you a resident regardless of days, and sometimes it lets you ignore days you'd otherwise have to count. This matters most in the US:
- Green card holders: you're a US tax resident from the day you get the card, no day count needed, and you stay one until you formally abandon it. See green card abandonment and I-407 timing.
- F, J, M, Q visas (students/scholars): often exempt individuals whose days don't count toward the Substantial Presence Test for a set number of years. See F-1 / OPT / H-1B transitions.
- H-1B and other work visas: fully countable days, you run the standard Substantial Presence Test.
- Long-term green card holders leaving the US: watch the 8-of-15-year rule, which can trigger the exit tax.
- Golden-visa and residency-by-investment holders abroad: a residence permit is immigration status, not automatic tax residency, see why a golden visa isn't tax residency.
- Digital nomads on remote-work visas: rules vary wildly; many still trip the 183-day line. Start with the digital nomad tax guide.
Putting it together: most people are on more than one route
Real situations cross routes. A US citizen working from Lisbon hits the country layer (Portugal's 183-day test), the federal layer (citizens are taxed worldwide regardless of residence, see the Foreign Earned Income Exclusion), and possibly a treaty tie-breaker. A snowbird flying between New York and Florida hits two state layers. An H-1B holder who travels home each summer hits the US federal layer plus their home country's rule.
The practical move is to count your days under every rule you touch, in real time, on each rule's own calendar. Tax Days does exactly this on your iPhone: log a trip once and it tracks your days against the 183-day rule for any country, the US Substantial Presence Test, Schengen 90/180, the UK SRT, and US state thresholds, warning you before you cross a line instead of after the year has closed.
Build your routing list once: write down every country and state you spent more than about 30 days in this year, then map each to its test using the tables above. If two jurisdictions both clear their threshold, you have a tie to resolve, that's your treaty-tie-breaker homework.
When a routing guide isn't enough
These guides will tell you which test applies and how to count, that's most of the battle. But once two jurisdictions genuinely both claim you, or you're changing domicile out of a high-tax state, or you're nearing an exit tax, the stakes justify a professional who can apply the specific facts. Bring them clean, contemporaneous day counts and they'll do far more with your money. The worst position is the opposite: a vague "about 170 days" guess discovered in an audit after the year is gone.
Frequently asked questions
How do I know which tax residency rules apply to me?
Work through three layers in order: the country where you spend the most time (usually a 183-day or domicile test), US federal status if you spend time in the US on a visa or green card (the Substantial Presence Test), and any US state that can claim you (its own day count plus a domicile test). Most people are governed by two or three of these at once.
Can I be a tax resident of a country and a US state at the same time?
Yes. Country, US federal, and US state residency are separate determinations on separate calendars. You can be a non-resident for one and a resident for another simultaneously, and a treaty tie-breaker that helps at the country level usually does nothing to a US state.
Does my visa change which residency test applies?
Often, yes. A US green card makes you a tax resident from day one regardless of days. F and J student/scholar visas can make you an exempt individual whose days don't count for a period. H-1B and most work visas count fully. Abroad, a golden visa or residence permit is immigration status, not automatic tax residency.
Which test applies if I split time between two US states?
Each state runs its own test. You'll usually have one domicile state (your true permanent home) plus a possible statutory-resident state if you keep a home there and exceed its day threshold. New York's day count treats any part of a day as a full day, so border-hopping snowbirds need precise records; California leans more on domicile and closer-connection facts than a fixed day count.
What happens if two countries both say I'm a resident?
If both are treaty partners, a tie-breaker resolves it in this order: permanent home, center of vital interests, habitual abode, then nationality. Without a treaty, you can be a dual resident and may need foreign tax credits to avoid being taxed twice on the same income.
Where should I start if I have no idea which rules apply?
List every country and US state where you spent more than about 30 days this year, then match each to its test using the tables in this guide. Run your dates through a day calculator for any jurisdiction you're near the line on, and track contemporaneously so your numbers hold up later.
Sources & further reading
Every rule on this page is drawn from primary sources. Verify the current law before making a residency decision.
- [1]Substantial Presence TestIRS
- [2]Alien Residency, Green Card TestIRS
- [3]New York income-tax residencyNY Dept. of Taxation & Finance
- [4]Tax on foreign income, UK residence and taxGOV.UK
- [5]OECD Model Tax Convention, Article 4 (Resident) tie-breakerOECD