Tax residency and double taxation: the 183-day rule is not what you think
Spending under 183 days in a country does not make you a non-resident of it. Each state applies its own test, and days are often only one part. People planning a move ask how many days they can spend at home, and the usual answer, 183, is often wrong. That figure comes from a clause about short work trips in tax treaties, while residence is set by each country’s own law, which may also look at your home, your family and your job. Two states can both claim you in the same year, and a treaty, where one exists, then applies a fixed order of tests to pick one. For a senior employee with a family and a house, the deciding point is rarely the day count: it is where your life is actually based, and whether you can prove the break with dated documents.
Your pay for this stay
Taxed only at home
| 183 days or fewer | Met |
|---|---|
| Foreign employer | Met |
| No local cost | Met |
Article 15(2) of the OECD model. It assumes a treaty between the two countries, often close to this model: read yours. This rule covers the pay for a stay, not tax residence.
Three different questions
| Question | Decided by | Main test |
|---|---|---|
| Am I resident here? | Each country’s own law | Varies: days, home, family, work |
| Two countries claim me: which wins? | Tax treaty, Article 4 of the OECD model | Home, vital interests, habitual abode, nationality |
| Is my short work trip taxed there? | Tax treaty, Article 15 of the OECD model | 183 days, foreign employer, no local cost |
Each country writes its own test
There is no world rule. The United Kingdom counts days, but also your home, your work and your ties: 183 days in a tax year makes you resident, yet far fewer can do so if you have a home or family there. Fewer than 16 days usually makes you non-resident.
That is why two countries can both claim you in the same year, and why leaving one does not by itself make you resident of the other.
When two countries both claim you
Most tax treaties follow the OECD model, whose Article 4 runs through a fixed order: where you have a permanent home, then where your personal and economic relations are closer, then where you habitually live, then your nationality. If all of that fails, the two tax authorities settle it between themselves. The same model removes double taxation: under Articles 23 A and 23 B, your country of residence either exempts income the other state may tax or credits the tax paid there.
A treaty only exists between the two countries that signed it, so check the actual text for your pair. A country with no income tax may have few treaties, or a narrow one.
Resident under the treaty
Country A
| Deciding test | Centre of vital interests |
|---|
Article 4(2) of the OECD model, which applies only if each country treats you as resident under its own law. Vital interests are looked at only if you have a home in both countries.
Where the 183 days come from
The number people remember comes from Article 15 of the same model, and it does a different job. It covers an employee sent to work in another country for a short time: that country does not tax the salary if the stay stays within 183 days in any 12-month period, the employer is not resident there, and no local establishment bears the cost. All three conditions apply, and none of them says anything about where you are resident.
A worked case: leaving the United Kingdom
Take a manager who moves to Singapore on a full-time contract and comes back to see family. Official guidance gives two automatic ways out: fewer than 16 days in the UK in the tax year, or 46 days if you were not resident in any of the three previous years, or full-time work abroad, averaging at least 35 hours a week, with fewer than 91 days in the UK and no more than 30 of them spent working. So 80 days at home with 20 working days passes. The same 80 days with 35 working days fails that test, and the answer then depends on the other tests and on your ties.
The UK tests can catch you the other way too: an only home in the UK for at least 91 days in a row, used on at least 30 days of the tax year, or a year of full-time work there. The year itself runs from 6 April to 5 April, so a departure in March leaves a few days of a tax year to deal with. Split-year treatment can divide the year of the move, but other conditions apply, and it is not open to someone who lives abroad for less than a full tax year before returning.
The same move, leaving Canada
Canada asks about ties instead of counting days. You usually become non-resident on the latest of three dates: the day you leave, the day your spouse or partner and dependants leave, and the day you become resident of the new country. So a parent who goes ahead in January while the family stays until the end of the school year has probably not left in January. Keep your main ties in Canada and the tax agency usually still treats you as a factual resident, wherever you sleep. Form NR73 asks it for an opinion on your status.
Three mistakes that come up often
Counting days from the wrong calendar: each country has its own tax year, and the Article 15 test runs over any 12 months, not one calendar year. Assuming a new residence ends the old one: nothing obliges your former country to agree until its own test is met or a treaty settles it. And forgetting to tell anyone: the United Kingdom expects form P85, or the residence pages of a Self Assessment return, from people leaving for good or for at least one full tax year of full-time work abroad.
Before you move
Keep dated proof of the break: the end of a lease, a new contract, school enrolment, the closure of local ties. If your family and your main home stay behind, expect your old country to keep claiming you whatever your day count says.
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Questions
Does living abroad for 183 days end my tax residency?
No. Each country applies its own test, and your home, family and work can keep you resident even with few days on its soil. Spending most of the year elsewhere helps, but it does not settle the question by itself. Check the rule of the country you are leaving, and keep dated proof that your life has moved.
Can I be tax resident in two countries at once?
Yes, because each country applies its own law without asking the other. Where a tax treaty exists, its tie-breaker gives one country the status of residence for treaty purposes, testing your permanent home first, then your centre of vital interests. Without a treaty, both may tax you, and relief depends on each country’s own rules.
Can I be tax resident nowhere?
It can happen on paper, usually for people who keep moving, but it is fragile. A former country may still claim you under its own test, and banks and new employers often ask for proof of a residence. Being resident nowhere rarely stays a stable position for someone with a family, property and a salaried job.
Sources
Figures 2026, checked on