Tax residence

Tax residence is the status that gives a country the right to tax a person as one of its residents. Each country decides it with its own test of facts: days spent, a home kept and the centre of your economic interests.

How Portugal and Spain test tax residence

Portugal (Código do IRS, article 16):

• You are resident if you stay more than 183 days, consecutive or not, in any 12-month period.
• With fewer days, you are resident if, on any day of that period, you have a home in conditions suggesting the intention to keep and occupy it as your habitual residence.
• Any full or partial day that includes an overnight stay counts as a day of presence.

Spain (Ley 35/2006 del IRPF, article 9):

• You are resident if you spend more than 183 days in Spain in the calendar year; sporadic absences count unless you prove tax residence in another country.
• You are also resident if the main core or base of your activities or economic interests is in Spain, directly or indirectly.
• Spain presumes, unless you prove otherwise, that you are resident if your spouse (not legally separated) and dependent minor children habitually live there.

How many days make you tax resident in Portugal?

More than 183 days, consecutive or not, in any 12-month period make you tax resident in Portugal, and any day that includes an overnight stay counts. You can also be resident with fewer days if you keep a home there in conditions suggesting you intend to keep and occupy it as your habitual residence.

Why a family can be resident in two countries

Each country applies its own test. A founder can count days carefully in Portugal and still be resident in Spain because the family lives there. When two countries both claim you, double tax conventions decide dual-residence cases, which is the problem in our case file on the Portugal UAE double tax treaty.

For families in the €2–20M range the gap is evidence, not law. Nobody keeps the calendar of days or the record of homes and income, and each bank holds a different declaration of residence. A regime such as IFICI only starts once residence is settled.

PWA designs and runs the operating layer around private wealth: in our wealth planning and structuring work we keep that record, so the family’s tax advisors work from facts. Before a move, a written second opinion shows what the evidence currently says.

Sources

• Autoridade Tributária e Aduaneira, Código do IRS, article 16, accessed 2026-10-04.
• Boletín Oficial del Estado, Ley 35/2006, article 9, accessed 2026-10-04.

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This entry is part of PWA’s plain-language glossary of terms used in modern family office architecture.