What the 183-day rule is
The 183-day rule is not a single law. It is a number that appears in 2 different places, doing 2 different jobs, and most confusion comes from mixing them up:
- A residence test in a country's own law. Spend 183 days there, counted the way that country counts, and you become tax resident in that country, usually taxed on your worldwide income. This is the rule most people mean.
- An employment rule in tax treaties. If you work in another treaty country for an employer that is not resident there, staying 183 days or fewer in any 12-month period can keep your salary taxable only where you are resident. It does not decide your residency at all.
Half of a 365-day year is 182.5 days, so 183 is the first full day past the halfway mark, which is why so many laws use it. The exact wording still matters, and it differs from country to country.
The 183-day rule by country
The table compares the day test in 12 countries. Read 3 columns before you trust a number: whether the law says 183 days or more, or more than 183 (so you need 184); which period it counts; and whether another test can make you resident with fewer days.
Day tests by country. Sources: statutes, tax authorities and PwC Worldwide Tax Summaries, linked in the text and listed under Sources (checked October 12, 2026).
| Country | Day test in the law | Period counted | Can make you resident with fewer days |
|---|---|---|---|
| Spain | More than 183 days | Calendar year | Main base of business or economic interests; spouse and minor children in Spain |
| Portugal | More than 183 days | Any 12 months starting or ending in the year | A home kept as your habitual residence |
| Cyprus | More than 183 days | Calendar year | The 60-day rule, with a home and a Cyprus business tie |
| Colombia | More than 183 days | Any 365 consecutive days | Extra tests for Colombian nationals |
| United Kingdom | 183 days or more | Tax year, April 6 to April 5 | An only home in the UK; enough ties from 16 days |
| Ireland | 183 days or more | Calendar year | 280 days over this year and last, unless this year has 30 or fewer |
| UAE | 183 days or more | Any 12 consecutive months | 90 days with a residence permit and a home, job or business |
| Georgia | 183 days or more | Any 12 months ending in the year | High net worth status |
| Singapore | 183 days or more | Calendar year | A continuous 3-year stay; a job straddling 2 years with 183 days in a row; a work pass valid for 1 year or more |
| Malaysia | 182 days or more | Calendar year | 90 days, if resident or present 90 days in 3 of the 4 previous years |
| Thailand | 180 days or more | Calendar year | None: the day count is the only test |
| United States | 183 weighted days, with 31 this year | 3 calendar years | A green card |
So a 182-day stay is safe from the day test in Spain but not in Malaysia (HASiL, Public Ruling No. 11/2017), and 180 days already makes you resident in Thailand (Revenue Department, Guide to P.N.D. 90). Spain also adds short trips abroad back into your Spanish days unless you prove tax residence in another country (LIRPF, article 9). Colombia counts any 365 days in a row, with the days you arrive and leave included (Estatuto Tributario, article 10), and Georgia any 12 months ending in the tax year (Tax Code, article 34). Singapore treats a foreigner whose work pass is valid for 1 year or more as resident, and reviews that when the job ends (IRAS, working out your tax residency).
How the 183 days are counted
Once you know the number, the counting rules decide whether you reached it, and how you count days for tax residency can move a stay from one side of the line to the other:
- Part days usually count in full. Ireland counts any part of a day spent in the country (Revenue), and so does the US (IRS), while the UK counts a day only if you are in the UK at the end of it (Finance Act 2013, Schedule 45, paragraph 22).
- The days need not be in a row. Portugal counts days consecutive or not (CIRS, article 16), and separate stays add up everywhere in the table.
- The window can roll. A calendar-year test starts again on January 1. A 12-month window, as in Portugal, the UAE and Georgia, can catch a stay that straddles New Year.
| October 1 to December 31, 2025 | 92 days |
|---|---|
| January 1 to April 30, 2026 | 120 days |
| Calendar-year test, 2025Under 183: not resident by days | 92 days |
| Calendar-year test, 2026Under 183: not resident by days | 120 days |
| 12-month window from October 1, 2025More than 183: resident by days | 212 days |
A country that counts the calendar year, such as Spain, sees 2 short stays. A country that counts any 12-month period starting or ending in the year, such as Portugal, sees 1 stay of 212 days.
Countries that can make you resident in fewer than 183 days
In several countries, 183 days is only the slowest way in. A shorter stay works when you add a home, a permit or a business:
- Cyprus, 60 days. You also need a permanent home in Cyprus, owned or rented, a business or job in Cyprus or a directorship of a Cyprus tax-resident company, held at any time in the year and not ended before December 31, and no more than 183 days in any other single country; since January 1, 2026 it no longer matters whether another country treats you as resident (PwC, Cyprus residence). The 60-day rule opens Cyprus non-dom residence to someone who spends most of the year abroad.
- UAE, 90 days. A residence permit holder with a permanent home, a job or a business in the UAE is resident after 90 days in any 12 consecutive months (Cabinet Decision No. 85 of 2022, article 4).
- Paraguay, 120 days. Tax residency in Paraguay rests on a presumption in its tax law: after more than 120 days in the country, that is your habitual residence, and so your domicile (Law 125/1991, article 152).
- Switzerland, 30 days. A stay of at least 30 days while working, or 90 days without working, makes you resident (DBG, article 3).
- The UK, from 16 days. Under the UK statutory residence test, someone who was UK resident in any of the previous 3 tax years and spends 16 days or more in the UK can be resident if they keep enough ties, such as family, a home or work there (GOV.UK).
- Portugal and Spain, no day minimum. Portugal's home test and Spain's economic interests test can make you resident with any number of days.
The UAE 90-day route: met and missed
Met
You hold a UAE residence visa, rent an apartment in Dubai on an annual lease, so it is available to you at all times, and spend 100 days in the UAE within 12 consecutive months. The permit, the home and the 90 days are all there, so you are resident.
Missed
You hold the same visa and spend the same 100 days, but in hotels, with no lease, job or business in the UAE. The 90-day route needs one of those ties, and 100 days is far short of the 183-day test, so you are not resident unless the UAE is your primary home and the center of your financial and personal interests (Cabinet Decision No. 85 of 2022, article 4(1)), which hotel stays with no UAE job or business do not show.
The US version: the substantial presence test
The US does not use a flat 183 days in a year. A visitor who is not a citizen or green card holder becomes a US tax resident under the substantial presence test: at least 31 days in the current year, and 183 days over 3 years counting every day this year, 1/3 of last year's days and 1/6 of the days from the year before (IRS, substantial presence test).
The weighting is what catches regular visitors. Spending 122 days a year in the US for 3 years in a row adds up to 183 weighted days, so a pattern that never comes close to half a year can still make you resident:
- This year (full days)
- Last year (1/3)
- 2 years ago (1/6)
Source: IRS, Substantial presence test (the IRS formula applied to each pattern) Worked examples of the formula, not data about real travelers. Totals of 183 or more pass the test: the 122-day and 150-day patterns do, the 120-day and 182-day patterns do not.
Show the numbers
| This year (full days) | Last year (1/3) | 2 years ago (1/6) | Total | |
|---|---|---|---|---|
| 120 days every year | 120 days | 40 days | 20 days | 180 days |
| 122 days every year | 122 days | 40.7 days | 20.3 days | 183 days |
| 182 days this year only | 182 days | 0 days | 0 days | 182 days |
| 150 this year, 120 in each year before | 150 days | 40 days | 20 days | 210 days |
There is a way out for some visitors. The closer connection exception treats you as a non-resident if you were in the US fewer than 183 days in the year, kept a tax home in 1 foreign country all year (or in 2, moving from the first to the second during the year and taxed as a resident in either or both), had a closer connection to that country, or to each of the 2, than to the US, and took no steps toward a green card; you claim it on Form 8840 by your return's due date (IRS, closer connection exception). US citizens never need the test, because the US taxes them on worldwide income wherever they live (IRS).
The 183-day rule in tax treaties
Most tax treaties follow the OECD Model, whose employment article uses the number for a different job. Salary for work done in the other country stays taxable only in your country of residence if all 3 conditions hold (OECD Model, Article 15(2)):
- You are in the other country for no more than 183 days in total in any 12-month period starting or ending in the tax year concerned.
- Your employer is not resident in that country.
- Your pay is not borne by a permanent establishment your employer has there.
If any of the 3 fails, the country where you work can tax the salary for the work done there from your first working day, so working remotely from another country on the payroll of a local subsidiary is taxable there at once. Article 15 covers employees only. A freelancer's business income falls under the business profits article instead, and stays taxable only at home unless you carry on business through a permanent establishment in the other country (Article 7(1)). Some treaties still keep a separate article for freelancers, the one the OECD dropped from its Model in 2000, and those built on the UN Model add a 183-day test: stay 183 days or more in any 12 months and the other country can tax the income from the work done there (UN Model Convention 2017, Article 14(1)(b)).
The 183-day myth: why fewer days does not mean no tax
The rule is often read in reverse: stay under 183 days in every country and you owe tax nowhere. It is a common mistake in planning taxes as a digital nomad, and it fails on the country you came from.
Leaving is a separate test from arriving
You leave Madrid at the end of 2025. In 2026 you spend 150 days in Portugal in short rentals, 120 in Thailand and the other 95 on the move, under every day test. Your spouse and minor children stay in the Madrid apartment. Spain presumes you are still resident while they live there, unless you prove otherwise (LIRPF, article 9), and with no tax residence in another country to show, it can tax your 2026 worldwide income.
Ending the old residency means giving up the home and ties as well as the days, and becoming non-resident for tax is easier to prove once a new country certifies you as its resident. Being resident nowhere at all, the perpetual traveler approach, leaves you without that certificate or any treaty protection. Even flag theory, which spreads companies and banks across countries, keeps 1 country as the tax residence that sets the bill.
Checking and proving your days
Tax offices ask where you slept, not only where you flew, so keep records that show both, and get a tax residence certificate from the country where you are resident, because that is what a treaty partner or a foreign payer will ask for.
Checking a stay against the 183-day rule
- Read the country's wording: "183 days or more" makes day 183 the one that counts, "more than 183" makes it day 184.
- Note the period it counts: calendar year, its own tax year or a 12-month window, and whether part days count.
- Check the rolling 12-month total, not only the calendar year, before you book a long stay.
- Run the weighted 3-year total if you visit the US every year.
- Mark the tests that need no days, in the new country and the one you left: a home, family or business.
David's note
I would never plan a year around landing on 182 days. Day counts get disputed at the margins: a missed flight, a part day that counts in full, a window that rolls over New Year. If you want a country's residency, clear its test by a few weeks; if you want to avoid it, stay well under and make sure your home and business are clearly somewhere else.
