The 183-day rule explained
"183 days" appears in many tax rules, but it does not mean the same thing everywhere. This page explains the main ideas in plain words. It is not tax advice.
Last updated · Sources checked on
Not tax advice
Tax residence depends on the law of each country and on the tax treaty between two countries, if there is one. Rules change and have exceptions. For your situation, ask the tax authority concerned or a qualified tax adviser.
Two different things called "the 183-day rule"
Our explanation
- National residence rules. Many countries treat you as tax resident if you spend a certain number of days there, often 183, but each country defines how days are counted and over which period, and many add other tests.
- Tax treaties. In treaties that follow the OECD Model, Article 15 uses 183 days for a different question: which country may tax a salary for work done abroad.
Spending fewer than 183 days somewhere does not automatically mean you are not resident there, and spending more does not automatically make you resident.
National rules differ: two official examples
Official rule
United Kingdom. You are UK resident for the tax year if you spend 183 days or more in the UK in that tax year; other tests (home, full-time work, ties) can also make you resident with fewer days. A day generally counts if you are in the UK at the end of the day (midnight), with exceptions (deeming rule, transit, exceptional circumstances). The tax year runs from 6 April to 5 April.
(source: HMRC, RDR3 statutory residence test; HMRC manual RFIG20710; GOV.UK, Income Tax)Official rule
United States. The substantial presence test requires presence on at least 31 days in the current year and 183 days over 3 years, counting all days of the current year, one third of the days of the year before, and one sixth of the days of the year before that.
(source: IRS, substantial presence test)Our explanation
These two examples show how much the counting can differ: midnights in one, any day of presence and a weighted three-year total in the other. Always use the definition of the country concerned.
Tax treaties: Article 15 of the OECD Model
Official rule
Article 15(2): a salary earned by a resident of one country for work done in the other country is taxable only in the country of residence if (a) the person is present in the other country "for a period or periods not exceeding in the aggregate 183 days in any twelve month period commencing or ending in the fiscal year concerned", (b) the employer is not resident in the other country, and (c) the salary is not borne by a permanent establishment the employer has in the other country.
(source: OECD Model Tax Convention 2017)Official rule
Commentary on Article 15, paragraph 4: all possible periods of twelve consecutive months must be considered, even overlapping ones. Example: 150 days between 1 April 01 and 31 March 02, but 210 days between 1 August 01 and 31 July 02: the 183 days are exceeded in the second period.
Paragraph 5: the "days of physical presence" method. Part of a day, the day of arrival, the day of departure and all other days in the country (weekends, holidays, sick days...) count; days in transit between two points outside the country do not. Paragraph 5.1: days during which the person is a resident of that country are not taken into account.
(source: OECD Model Tax Convention 2017)Official rule
The 2025 Update of the OECD Model keeps the wording of Article 15(2)(a); the changes it lists for the Commentary on Article 15 concern other paragraphs.
(source: 2025 Update to the OECD Model)Our explanation
The OECD Model is a template. Each real treaty is negotiated between two countries and may differ: read the treaty that applies to you. And Article 15 only works together with the other two conditions (employer, permanent establishment), not on its own.
Resident in two countries? The tie-breaker
Official rule
Article 4(2) of the OECD Model: a person resident in both countries under their laws is treated as resident only of the country where he or she has a permanent home available; if there is one in both, the country with which personal and economic relations are closer (centre of vital interests); if that cannot be determined, the country of habitual abode; then nationality; and finally the two tax authorities settle it by mutual agreement.
(source: OECD Model Tax Convention 2017)What our counter does
Our explanation
The 183-day counter counts your days in one country with the method you choose (any presence, midnights, or full days), per calendar or tax year, for the 12 months ending on a date, and the highest count over all 12-month periods that start or end in a year. It does not decide whether you are resident.
Frequently asked questions
If I spend fewer than 183 days in a country, am I not tax resident there?
Not necessarily. Many countries also look at your home, family, work or economic interests, and some use other day counts. Fewer than 183 days does not by itself settle your residence.
Do the day of arrival and the day of departure count?
It depends on the rule. The OECD Commentary on Article 15 counts part of a day, the day of arrival and the day of departure. The UK statutory residence test generally counts a day if you are in the UK at midnight.
Calendar year or any 12 months?
It depends on the rule. National rules often use the tax year (in the UK, 6 April to 5 April). Article 15 of the OECD Model looks at any twelve-month period commencing or ending in the fiscal year concerned.
Other guides
The Schengen 90/180 rule explained
The official rule in plain words, the rolling window, the Commission's worked examples and common mistakes.
EES (Entry/Exit System) explained
What the EES records at the border, who it applies to, and what it changed since 10 April 2026.
ETIAS explained
The future travel authorisation for visa-exempt travellers: official facts and what is still unknown.
Official sources
- OECD Model Tax Convention on Income and on Capital, Condensed Version 2017 (PDF)
- OECD: The 2025 Update to the OECD Model Tax Convention (PDF)
- GOV.UK (HMRC): RDR3 Statutory Residence Test notes
- GOV.UK (HMRC): RFIG20710, meaning of a day spent in the UK
- GOV.UK: Income Tax
- IRS: Substantial Presence Test
Sources checked on 1 November 2026.