what is the 183 day rule 
the 183 day rule refers to a threshold used by most countries to determine whether an individual should be considered a resident for tax purposes this number is often used in a tax context because it marks the point at which someone has spent more than half the calendar year in a particular jurisdiction in the u s the internal revenue service irs uses a formula to determine whether people who are neither u s citizens nor permanent residents should be considered residents for taxation this is called the substantial presence test one of its criteria includes the question of whether an individual has spent 183 days in the u s based on a calculation that considers their combined physical presence in a given tax year and the two years prior 1understanding the 183 day rulemany countries around the world use the 183 day threshold to broadly determine whether to tax someone as a resident because it marks the majority of a year these include canada australia and the united kingdom for example generally this means that if you spent 183 days or more in the country during a given year you are considered a tax resident for that year each nation maintaining a 183 day rule has its own criteria for applying it in practice for example some use the calendar year for the accounting period whereas others use a fiscal year some include the day the person arrives in the country others do not some countries have even lower thresholds that trigger tax residency for example switzerland considers you a tax resident if you have spent more than 90 days there 3the irs and the 183 day rulethe irs uses a more complicated formula to determine whether someone passes its substantial presence test and is subject to u s taxes as a result the person in question must the 183 day presence threshold is not based off a total sum of days present rather it is calculated by adding the following other irs terms and conditionsthe irs generally considers someone to have been present in the u s on a given day if they spent any part of a day there but there are some exceptions days that do not count as days of presence include u s citizens and resident aliensstrictly speaking the 183 day rule does not apply to u s citizens and permanent residents who are required to file tax returns regardless of their country of residence or the source of their income however such individuals may exclude at least part of their overseas earned income up to 126 500 in 2024 from taxation provided they meet a physical presence test in a foreign country and paid taxes there 2 to meet this physical presence test the person needs to be present in the country for 330 complete days in 12 consecutive months 4individuals residing in another country in violation of u s law will not be allowed to have their incomes qualify as foreign earned 5u s tax treaties and double taxationthe u s has tax treaties with other countries that help determine jurisdiction for income tax purposes and to avoid double taxation these agreements contain provisions for the resolution of conflicting claims of residence 