Portugal's 183-Day Tax Residency Rule
More than 183 days in any rolling 12-month period makes you a Portuguese tax resident. Here is exactly how the count works.
Last verified: July 2026
In short: you become a Portuguese tax resident if you spend more than 183 days in Portugal during any rolling 12-month period. Any day with an overnight counts. The window is not the calendar year, and a home kept in Portugal can trigger residency even below 183 days.
- Threshold
- More than 183 days
- Counting window
- Any rolling 12 months
- A day counts if
- You spend the night
- Other residence test
- Habitual residence (home kept)
- Tax year
- Calendar year
- Legal basis
- CIRS, Article 16
The rule
Portugal treats you as a tax resident for a period if you spend more than 183 days there within any 12-month window. Two points decide most real cases:
- The window rolls. The 183 days are measured across any 12-month period, not 1 January to 31 December. Two stays in different calendar years can combine inside one window.
- A day means an overnight. Any day you sleep in Portugal counts, so arrival and departure days with a night both count.
How to count it
- List every Portugal trip with arrival and departure dates.
- Count each day with an overnight, including arrival and departure days.
- Total the days inside a single 12-month window, then slide that window across your whole travel history.
- If any 12-month window exceeds 183 days, the day-count test is met.
Example. 100 days in Portugal from October to December, then 100 more from February to May.
No single calendar year hits 183. But both stays sit in the same rolling window (October to the following October) and total 200 days, so the test is met.
Beyond the day count
The 183-day count is one route in, not the only one. Portugal can also treat you as resident if you keep a home there on any day of the period in conditions that suggest you intend to occupy it as your habitual residence. And if another country also claims you, a double-tax treaty decides residency through tie-breaker rules such as permanent home and centre of vital interests.
Official source: Article 16 (Residência) of Portugal's Personal Income Tax Code (Código do IRS), on the Autoridade Tributária e Aduaneira (Portal das Finanças).
AtlasDays tracks Portugal's 183-day rule automatically
Log your trips once. AtlasDays counts every rolling 12-month window for you, privately on your iPhone, and warns you before you cross 183 days.
Get AtlasDays on the App StoreFAQ
How many days can you stay in Portugal without becoming a tax resident?
Up to 183 days in any rolling 12-month period. Cross more than 183 in any window and the day-count test is met.
Is the 183-day rule based on the calendar year?
No. It uses any rolling 12-month period, so a stay split across two years can still cross the line.
Can you be resident with fewer than 183 days?
Yes, through the habitual-residence test if you keep a home in Portugal in the relevant conditions.