Move to Portugal and the tax question is not whether you meant to stay. It is how many days you were there — and whether you kept a home.
Two doors into residency
Portugal's residency tests live in Article 16 of the Personal Income Tax Code (the Código do IRS, or CIRS). You are a tax resident if you meet either of two conditions in the relevant period (PwC summary of Portuguese residence rules):
- You spend more than 183 days in Portugal, consecutive or not; or
- You keep a home there on any day of the period, in conditions that suggest you intend to hold and occupy it as your habitual residence.
You only need to walk through one — and the stakes are not small. A Portuguese tax resident is taxed on worldwide income, while a non-resident is taxed only on Portuguese-source income (PwC, taxes on personal income).
| Status | Taxed on |
|---|---|
| Resident | Worldwide income, at progressive rates (12.5%–48% for 2026) |
| Non-resident | Portuguese-source income only |
The 183 days — over a rolling window
Here is the detail that catches people. Portugal does not only look at the calendar year. The 183-day count is measured over any 12-month period that starts or ends in the fiscal year concerned (PwC). The OECD's summary of Portugal's residency rules sets out the same 183-day and habitual-residence structure.
A rolling window behaves differently from a calendar one. Days from the end of one year and the start of the next can combine to pass 183 across a twelve-month stretch that no single January-to-December view would reveal. If your life is spread across borders, the only reliable way to know where you stand is to track presence continuously — not to total a single year the following April.
This is a different regime from the Schengen 90/180 rule, which limits short-stay travel over a rolling 180 days. Tax residency and border-stay limits are separate systems with separate clocks — we pull them apart in Schengen 90/180 vs. the 183-day tax rule.
A home can be enough on its own
Even below 183 days, Portugal can treat you as resident if you keep a dwelling there under conditions that imply you mean to keep it as your habitual home (OECD). There is no day count attached to this test: an available home you intend to return to can establish residency by itself. It is a judgement about your ties, not a tally.
Residency can start on your first day
Portugal also surprises arrivals from countries with all-or-nothing tax years. Residency begins on the first day of presence and ends on the last day, so you can be resident for only part of a year (PwC).
That is the opposite of Spain, which has no split-year treatment and fixes your status for the whole calendar year at once — a contrast worth understanding if you are weighing the two, and one we cover in Spain's 183-day tax residency rule. Because partial-year residency turns on the exact date you arrived or left, those dates matter — not only the annual total.
What changed in 2024: NHR is gone
For years Portugal drew newcomers with the Non-Habitual Resident (NHR) regime. It has closed to new entrants, and the government replaced it with a narrower scheme — the Tax Incentive for Scientific Research and Innovation (IFICI), regulated by Ministerial Decree No. 352/2024/1, published on 23 December 2024 and applying to people who became Portuguese tax residents from 1 January 2024 (KPMG flash alert).
IFICI grants a 20% rate on eligible Portuguese employment and self-employment income for a 10-year period, with an exemption for many categories of foreign-source income — but eligibility is far tighter than NHR's, aimed at academic, research, and highly qualified roles at qualifying employers. Whether you qualify is fact-specific and the rules are new, so treat any incentive as something to confirm with the Portuguese tax authority and a qualified adviser, not a given.
What has not changed is the residency test itself. Incentive or none, the 183-day count and the home test decide whether Portugal taxes your worldwide income.
What this asks of you
Portuguese tax residency rests on facts you are expected to be able to show: how many days you were physically in Portugal across a rolling twelve months, and the exact dates you arrived and left. Those are precisely the facts people reconstruct from memory — and precisely the facts a tax authority can check against border records.
The quiet defence is a contemporaneous, day-by-day record. That is what Countly keeps: it counts the days you spend in each country automatically, on your phone, and flags you as you approach thresholds like 183 days — so "how long was I in Portugal?" is a number you already have, not one you rebuild from boarding passes. It stays on your device; there is no account and nothing to track you.
This is general information, not legal or tax advice. Rules vary by country and change — check the official Portuguese tax authority (Autoridade Tributária) guidance and a qualified adviser for your situation.