Verified 2026-06-04 against each tax authority’s own source. We never fabricate a threshold or citation.
🇵🇹 Portugal
Test: More than 183 days (or a Portuguese home kept as your habitual residence)
Count over: Calendar year (1 Jan–31 Dec), but the 183-day count is measured over ANY rolling 12-month window starting or ending in the year. Portugal applies partial-year residency.
Portugal applies partial-year residency — you become resident from your first day of presence, so arrival/departure timing materially changes the result.
Source: Autoridade Tributária e Aduaneira (AT) — Portal das Finanças · verified 2026-06-04🇪🇸 Spain
Test: More than 183 days, OR Spain is your centre of economic interests
Count over: Calendar year (año natural, 1 Jan–31 Dec). NO split-year — you are resident for the whole year or not at all. Sporadic absences count toward the 183-day total unless you prove tax residency elsewhere.
Spain has no split-year: residency makes you taxable on worldwide income for the entire calendar year. Days abroad ('sporadic absences') still count toward 183 unless you hold a foreign tax-residency certificate.
Source: Agencia Estatal de Administración Tributaria (AEAT) · verified 2026-06-04🇩🇪 Germany
Test: A home available to you (Wohnsitz) — OR habitual abode (generally >183 days)
Count over: Calendar year — but Germany does NOT use a single-year 183-day count as its primary trigger. A home available to you (a 'Wohnsitz', §8 AO) makes you resident from day one; a habitual abode (§9 AO, generally >6 months' continuous presence) is the alternative.
Germany does NOT rely on a 183-day count: simply keeping a home available to you in Germany makes you resident on worldwide income from day one, regardless of days present.
Source: Bundeszentralamt für Steuern (BZSt) — Abgabenordnung §§8–9 / EStG §1 · verified 2026-06-04🇹🇭 Thailand
Test: 180 days or more (aggregate) in the calendar year
Count over: Calendar year (1 Jan–31 Dec). A pure aggregate day count — no ties, no permanent-home element, nationality irrelevant.
Since 1 Jan 2024, a Thai tax resident is taxed on foreign income whenever it is remitted (brought) into Thailand — a major change from the old same-year-only rule. The day count itself is mechanical; the remittance consequence is not.
Source: The Revenue Department of Thailand (กรมสรรพากร) · verified 2026-06-04🇨🇾 Cyprus
Test: More than 183 days — or the conditional 60-day rule
Count over: Calendar year (1 Jan–31 Dec). Income Tax Law 118(I)/2002.
Cyprus also offers a '60-day rule' (60+ days PLUS Cyprus business/employment/directorship PLUS a permanent Cyprus home AND no 183+ days in any other state AND not tax-resident elsewhere). It is a 4-condition cumulative test — this tool only flags it for you to verify, never confirms it.
Source: Cyprus Tax Department (Τμήμα Φορολογίας), Ministry of Finance · verified 2026-06-04🇦🇪 United Arab Emirates
Test: 183 days in any 12-month window — or the conditional 90-day route
Count over: ANY consecutive 12-month period (not a fixed calendar year). All days or parts of a day count; they need not be consecutive.
The UAE has 0% personal income tax, so this 'tax residency' status mainly affects your eligibility for a Tax Residency Certificate (TRC) and tax-treaty relief — it does not create UAE income tax.
Source: Federal Tax Authority (FTA) — Cabinet Decision No. 85 of 2022 · verified 2026-06-04🇬🇧 United Kingdom
Test: Decided by the Statutory Residence Test (SRT) — this tool flags only the clear-cut day-count cases
Count over: UK tax year 6 April–5 April (NOT the calendar year). Count UK days only.
UK residence is decided by the Statutory Residence Test (SRT/RDR3) — a multi-step statutory test with detailed home/work/tie definitions. This tool only indicates a clear day-count case; for anything else, use HMRC's official residence-status checker.
Source: HM Revenue & Customs (HMRC) · verified 2026-06-04🇺🇸 United States
Test: Green card → resident; otherwise the Substantial Presence Test (weighted 3-year formula)
Count over: Calendar year. Two tests: the Green Card Test and the Substantial Presence Test (a weighted 3-year day formula).
US citizens and green-card holders are taxed on worldwide income regardless of days. For other non-citizens, residence turns on the Substantial Presence Test — a weighted 3-year formula with many exclusions (student/teacher exempt days, the Form 8840 closer-connection exception, treaty tie-breakers).
Source: Internal Revenue Service (IRS) · verified 2026-06-04