183 day rule tax residency, explained with numbers

By Skyler Bissell · November 2, 2026

Land in Madrid on 1 July 2026 and stay through New Year's Eve, and you have spent 184 days in Spain. Spanish law needs more than 183, so that one extra day makes you resident for the whole of 2026, January included. Land in Milan a day later, on 2 July, and you reach 183 days. Italy needs a majority of the year, and 183 out of 365 is a majority, so you are Italian resident for all of 2026 too. One arrival date, two countries, two different answers.

What the 183-day rule decides

Residence is the first question any tax system asks, because it sets how much of your income the country can reach. A resident is usually taxed on everything, wherever it was earned. A non-resident is taxed only on income from that country. Day counting is the most visible way to settle the question, and that's why "183 days" gets repeated so often. Within a single country, though, it is rarely the only test and often not the decisive one.

The same number also turns up in a different place: the employment article of tax treaties, which decides whether a country can tax the salary of someone who works there briefly. That rule makes nobody resident. It works on top of residence, after each country's own law has spoken, and our guide to working remotely for a US company from Europe quotes its wording in full. This page is about the domestic tests, the ones that decide whether you file as a resident at all.

For a move, residence matters in two ways. It decides which country gets your salary for the rest of the year, and for the months before you arrived it can decide whether the new country sees your old income too. The second question is the one that catches people. It turns on whether the country splits the arrival year or treats it whole.

How six countries count the days

Here are the domestic rules for six countries, read from each statute or tax authority on 2 November 2026. Each row names its country, so any line can be lifted on its own.

The day count is the least decisive column. The other tests decide whether you were ever going to get to count, and the arrival column decides how much of your year the new country can see.

Spain and Italy: the arrival year is all or nothing

Spain's rule sits in article 9 of the income tax law, and the Boletín Oficial del Estado consolidated text asks for presence of "más de 183 días, durante el año natural". The same law makes the tax period the calendar year, and article 13 allows a shorter period in a single case, the taxpayer's death. So Spain has no split year in its own law. Pass the test in the year you move and you are a resident for all twelve months, which means your worldwide income for the year, the salary you earned before the move included, is in scope. Article 80 credits the foreign tax already paid on that income, and where a treaty's tie-breaker applies, the months before arrival can be assigned to your old country. That treaty step is where an adviser earns their fee.

Italy rewrote its test for tax years from 2024. The Agenzia delle Entrate's circular 20/E lists four connections, any one of which held for the majority of the year makes you resident: civil-law residence, domicile (the centre of your personal and family relationships), physical presence, or registration in the population register. Registration used to settle the question outright. It is now a presumption you can rebut. The circular also says a remote worker who spends 183 days in Italy becomes resident on presence alone, and is then taxed on income "ovunque prodotti", wherever it was produced.

Italy also has no split year in its own law. The circular names three treaties that write one in, those with Germany, Switzerland and Panama, under which residence in the first country ends the day after the move. A mover from anywhere else is left with the treaty tie-breaker. This all-or-nothing year is the reason both countries' expat regimes count the arrival year as year one, which our guide to how long expat tax regimes last walks through. It cuts both ways. A July arrival who is resident by days spends regime year one on six months of salary. A late-autumn arrival who is not resident that year (too few days, and no family or economic base already in the country) starts the clock the following January, with a full first year.

The practical difference between the two countries comes down to one day. Spain's "more than 183" means 184 days is the first one that counts. Italy's "majority of the year" means 183 days is already enough in a 365-day year. A 2 July arrival who stays to 31 December is resident in Italy by days and not in Spain, though Spain's economic-interests test can still catch the same person.

Germany splits the year, and the whole salary still sets the rate

Germany has no 183-day test. Under section 8 of the German Fiscal Code, you have a residence where you hold a dwelling in circumstances that show you will keep and use it. Rent a flat in Berlin, move in, and you are resident from that day. Without a dwelling, section 9 of the Fiscal Code treats a continuous stay of more than six months as a habitual abode "from the beginning", with short interruptions ignored. Six months is the closest Germany comes to a day count, and the six months need not fall in one calendar year.

The arrival year is split. Income tax is still an annual tax, but income from before you became resident is kept out of the German base, except for German-source income, which section 2(7) of the Income Tax Act pulls into the same assessment. Then section 32b of the same act, the progression proviso, adds the foreign salary back in for one purpose only: finding the rate. Germany works out the rate as if you had earned the whole year's income here, then applies that rate to the part it may tax.

Here is what that does to one salary in our engine. Take a single filer on a EUR 120,000 salary (about $133,929) who moves to Berlin on 1 July and earns EUR 60,000 there before the year ends.

• Berlin, resident all year on EUR 120,000: €31,608 of income tax.
• Berlin, arrival year with the progression proviso: about €15,804 on the EUR 60,000 earned after arrival, which is half the full-year bill, because the rate comes from the whole year's pay.
• Berlin, the same EUR 60,000 taxed as if it were the whole year's income: €9,399.

The gap between the last two lines is the progression proviso at work. People hear "split year" and picture half a salary taxed at half-salary rates, whereas Germany taxes that half at the full salary's rate. The figures are income tax before the solidarity surcharge and church tax. Halving the full-year bill is an approximation: the real assessment deducts German social contributions only for the months worked in Germany, and foreign contributions do not reduce the rate base, so the true arrival-year figure tends to land slightly above the one shown here.

Portugal and the UK write the split into the statute

Portugal counts a rolling window. Article 16 of the IRS code, on the Autoridade Tributária's code page, makes you resident after more than 183 days, consecutive or not, "em qualquer período de 12 meses com início ou fim no ano em causa": in any 12-month period that begins or ends in the year. A home you appear to intend as your habitual residence is enough on fewer days. Once either test is met, residence runs from the first day you were present, and it ends on the last day you are present when you leave. A July arrival who stays into the next year is resident from July, and the months before stay outside the Portuguese base. Portugal's tax regime for new residents is a separate question that this page does not price.

The UK's statutory residence test, set out in HMRC's RDR3 guidance note, runs in a fixed order. First the automatic overseas tests: fewer than 16 days in the tax year if you were UK resident in any of the previous three years, fewer than 46 if you were not, or full-time work abroad with fewer than 91 UK days and fewer than 31 UK days of more than three hours' work. Then the automatic UK tests: 183 days or more, or a UK home held for a 91-day stretch under conditions. Anyone left over goes to the ties test, where family, accommodation, work and past days lower the number of days you can spend before becoming resident.

A UK resident is resident for the whole tax year, but HMRC's note says that year "may be split into a UK and an overseas part" when a statutory case fits. Arrivals have five of them, cases 4 to 8 in HMRC's residence manual, among them "Starting full-time work in the UK" and "Starting to have a home in the UK only". Whether a case fits is a fact question, so a mid-year mover should check the case conditions before assuming the split. We do not compute the UK's regime for foreign income and gains.

The Netherlands makes the useful counterexample. The General State Taxes Act, article 4, says only that where someone lives "wordt naar de omstandigheden beoordeeld", is judged by the circumstances. No day count appears anywhere in the Dutch test. The "183-dagenregeling" on Dutch tax pages is the treaty wage rule, and it applies after residence has been settled.

The US counts days for visitors and never for its citizens

The American version is a formula. Under the IRS substantial presence test, a non-citizen is a US resident for the year after at least 31 days in the current year and 183 days across three years, counting every day this year, a third of last year's days and a sixth of the year before. Any part of a day counts. Spend 122 days a year in the US, every year, and the formula gives 122 plus about 40.7 plus about 20.3, which is 183. Four months a year, every year, makes a visitor a resident by the third year.

Students, teachers, trainees and diplomats on certain visas can exclude their days, and someone who passes the test can still be a non-resident under the closer connection exception if their tax home and ties sit in another country. Those carve-outs are narrow, and they need a form filed to claim them.

For a US citizen the count never starts. The IRS page for US citizens and resident aliens abroad says filing rules are "generally the same whether you are in the United States or abroad", and that you are "subject to tax on worldwide income from all sources". An American who spends 365 days in Lisbon is a Portuguese resident and is still filing a federal return. The foreign earned income exclusion and foreign tax credits reduce what is owed. They are both claimed on that return. US state residency is a third layer with its own tests, and some states hold on after a move abroad.

Staying under 183 days is a weaker shield than it looks

Every country above has a way to make you resident without the days. Spain's second test looks at where your economic activity or interests are centred, and the law presumes residence when your spouse (not legally separated) and dependent minor children live in Spain. Italy's domicile test looks at where your personal and family relationships are centred, and a population-register entry counts unless you prove otherwise. Germany asks only whether you hold a dwelling you will keep and use. Portugal asks whether you hold a home you intend as a habitual residence. A person with a lease, a spouse and a payroll in one of these countries is resident there on day one, whatever the calendar says.

The reverse also holds. Being under 183 days in your old country does not by itself end residence there. Spain counts sporadic absences as days in Spain unless you prove residence somewhere else, and the UK's 16-day and 46-day tests show how few days a recent resident may keep and still be clear of the UK automatically. When both countries can claim you, the treaty tie-breaker settles it, and our explainer on how tax treaties work covers the order of its tests.

What to write down before the move date is fixed

The arrival date is often the one variable a mover controls, and it is worth choosing with a calendar open. Keep three things for the year you move: a dated log of days in each country, the date you signed or took up a lease, and the date your new payroll started. Those are the facts every test above reads.

Then price the full year after residence. Our pillar on how countries tax your salary explains the brackets and contributions that start applying, the take-home pay by country ranking shows the resident outcome on one salary across every country we model, and you can run your own move through the calculator once the residence question is settled.

FAQ

Does the day I arrive count toward 183 days?

It depends on the country. Italy counts any fraction of a day as a whole day, so a plane landing at 23:00 counts that date. Portugal counts any full or partial day that includes a night spent in the country. The UK counts the days on which you are in the UK at midnight. The US counts any day on which you are physically present at any time. Keep boarding passes and dated receipts for both ends of every trip.

Can I be tax resident in two countries in the same year?

Yes. Each country applies its own test without asking what the other one decided, so a mid-year mover can pass both. A tax treaty between the two countries then picks one residence for treaty purposes through its tie-breaker, which looks at your permanent home and the centre of your personal and economic life before it looks at days.

When does tax residence end if I leave mid-year?

The same tests run in reverse. Portugal ends residence from the last day you are present. Spain and Italy look at the whole calendar year, so someone who leaves Madrid or Milan in March is usually non-resident for that year, unless an economic base or family left behind keeps them in (or, in Italy, a population-register entry that was never cancelled). The UK has departure split-year cases, among them starting full-time work overseas. Germany's residence ends once you give up both the dwelling and the stay.

The statutory rules on this page were read from the linked primary sources on 2 November 2026. The Berlin figures are cityparity engine outputs for a single filer with no children, current model rules, income tax only. The engine computes a full calendar year of residence; the arrival-year line is half of the full-year income tax, which approximates the progression proviso and excludes the solidarity surcharge, church tax and social contributions. No figure on this page is a residence determination, and no treaty tie-breaker outcome is assumed. Calculation methodology.