What is the 183-day rule?

The idea: present for more than half the year

Most tax systems need a simple, checkable way to decide who lives there. Physical presence is the bluntest and fairest proxy, and 183 days is the smallest whole number of days that is more than half of a 365-day year. Spend the majority of a year in a country and it is hard to argue you live somewhere else — so crossing the line typically makes you a tax resident, which in most countries means tax on your worldwide income, not just what you earned locally. In many systems even a part-day counts as a full day of presence, so arrival and departure days both go on the tally.

The same number, measured differently

"183 days" hides real variation in which days are counted over what window:

• Calendar year — the most common form: 183+ days between January 1 and December 31. Spain, Italy, France, and Canada's sojourner rule all count this way.
• Tax year — same test, different year: the UK's Statutory Residence Test runs April 6 to April 5, and Australia counts July to June.
• Rolling 12 months — the window slides daily instead of resetting: the UAE, Brazil, and Morocco use versions of this. (See how rolling windows work.)
• Weighted formulas — the US Substantial Presence Test reaches its 183 by adding this year's days to a third of last year's and a sixth of the year before.
• Different numbers entirely — some countries set the bar elsewhere: India's 182 days, Thailand's 180, the UAE's 90-day route, or Cyprus's 60-day regime for people who want in rather than out.

Why staying under 183 days isn't the whole story

The day count is usually the automatic test, not the only one. Most countries can still claim you below 183 days if your life is anchored there — a permanent home, a spouse and children, your main economic interests. Spain, France, and Germany all have ties-based tests that operate independently of the count, and the UK's SRT explicitly scales its day thresholds by your ties. Two countries can also claim you at once, which is where tax-treaty tie-breaker rules decide the winner — occasionally producing surprises like Canada's deemed non-resident status.

The 183-day rule in US states

Does Florida have a 183-day rule? Not as a tax test — Florida has no state income tax, so there is nothing to be resident for. The number still matters when you leave a taxing state for Florida: spending 183+ days there, alongside a Florida home, licence, and declaration of domicile, is the evidence that convinces your old state you have genuinely changed domicile. See Florida domicile and the 183-day rule.

How does California count 183 days? It largely doesn't. California uses a facts-and-circumstances domicile test — where your closest connections are — plus a presumption that anyone in the state for more than nine months of the tax year is a resident. Staying under 183 days is not a safe harbour if your home, family, or business remain in California. See California residency and audit risk.

Does New York use 183 days? Yes, as a statutory residency test: spend more than 183 days in New York State in the year and maintain a permanent place of abode there, and you are taxed as a resident even if your domicile is elsewhere. Any part of a day counts as a day. See New York's 183-day statutory residency rule.

Counting your own days

Every version of the rule reduces to the same discipline: know exactly how many days you have spent where, on the right window, with arrival and departure days handled the way that country handles them. The free 183-day rule calculator totals your days in any country over a calendar year or rolling 12 months from your trip dates, and the tax residency rulebook has the country-by-country details — thresholds, windows, and the ties tests that sit behind them.

Sources

• IRS — Substantial Presence Test
• HMRC — RDR3: Statutory Residence Test guidance
• Canada Revenue Agency — Determining your residency status