Spain is the only country in this set with a land border with Portugal, and that changes the shape of the problem. Nobody flies here from Badajoz. People move gradually, keep the old flat, keep the old bank, keep going back at weekends — and end up with two countries each holding a plausible view about where they live.
Portugal's test, and only Portugal's
CIRS art. 16 asks two questions. Have you spent more than 183 days, consecutive or not, in Portugal in any 12-month period beginning or ending in the year? Or do you keep a home here, on the last day of that period, in conditions that imply you intend to hold it as your habitual residence?
- Residence starts on the first day of the stay (art. 16 n.º 3), and backdates to 1 January if you were resident on any day of the previous year.
- It ends on the last day of presence (art. 16 n.º 4).
- Each status in a split year is assessed separately (art. 15 n.º 3).
Spain applies its own test and it is not this one. Our sources do not hold Spanish domestic law, so this page does not describe it — and that omission is deliberate rather than an oversight, because the two tests can both say yes and the resolution then depends on the convention's tie-breaker rather than on either country's own rule.
What Portugal taxes once you are resident
Everything, under CIRS art. 15 n.º 1 — Spanish rent, Spanish dividends, a Spanish salary, gains on Spanish shares. Non-residents are taxed only on Portuguese-source income under n.º 2, which is why the date residence begins is worth pinning down rather than approximating.
The 1993 convention
The convention between Portugal and Spain was signed in Madrid on 26 October 1993, approved for ratification by Resolução da Assembleia da República n.º 6/95 and ratified by Decreto do Presidente da República n.º 14/95, published on 28 January 1995.
Its pension articles are 18 and 19, and the interesting part is a single word. Article 18 gives private pensions from past employment to the state of residence, subject to article 19(2). Article 19(1)(a) covers "as remunerações, excluindo as pensões" — remuneration, excluding pensions — so pensions are pushed out of the government-service paragraph and into 19(2).
For the same reason this page prints no withholding ceilings on dividends, interest and royalties. They sit in articles 10, 11 and 12 of the convention and they are readable in the original.
Relief: the lesser-of credit
Where both countries tax the same income, CIRS art. 81 relieves it, and the amount is not simply the Spanish tax. It is the lesser of the tax actually paid in Spain and the fraction of Portuguese tax attributable to that income. If Spain charged more than Portugal would have, the excess is not refunded.
- n.º 2 — the credit is capped at the treaty rate, so tax withheld above it is reclaimed in Spain, not here.
- n.º 3 — what cannot be used this year carries forward five tax periods.
- n.º 9 — income the convention exempts with progression is still aggregated to set the rate on the rest, so exempt income raises the bill on everything else.
- n.º 10 — where the convention puts the credit obligation on the source state, Portugal gives no credit at all. Relief exists once, and the treaty decides where.
Filing here
| Item | Where it goes |
|---|---|
| Spanish income of any category, and the Spanish tax paid | Anexo J |
| Any account held outside Portugal | Folha de rosto, quadro 11 |
| Self-employment carried on here | Anexo B, or C under organised accounting |
| Gains | Anexo G, or G1 |
| IFICI or a running NHR | Anexo L |
The return is filed between 1 April and 30 June and the Code applies 30 June whether or not it is a business day. Immediately after submission it shows as received and awaiting validation, with the declaration number still empty — confirm a filing by its reception date rather than by a number that has not been assigned yet.
How many days in Portugal make me tax resident?
More than 183, consecutive or not, in any 12-month period beginning or ending in the year. But the day count is only one limb of CIRS art. 16: keeping a home here in conditions that imply you intend to hold it as your habitual residence makes you resident with no day count at all.
Can Spain and Portugal both treat me as resident?
Yes. They apply different domestic tests and both can answer yes. The 1993 convention then has a tie-breaker to allocate you to one of them for treaty purposes.
Does Portugal tax my Spanish rental income?
Once you are resident here, yes — CIRS art. 15 n.º 1 puts worldwide income in the Portuguese base. Spain may also tax it as the source state, and CIRS art. 81 relieves the overlap with a credit that is the lesser of the Spanish tax paid and the Portuguese tax on that income.
Who taxes a Spanish public-service pension?
Article 19(2) of the convention decides it, because article 19(1)(a) covers remuneration "excluding pensions" and pushes them into 19(2). Our copy of the convention is a scan whose columns interleave and we could not read 19(2) cleanly, so we do not state the outcome — read the original PDF for that paragraph.
Do I have to declare a Spanish bank account that earned nothing?
Yes. Quadro 11 of the Modelo 3 folha de rosto has no income threshold, and being authorised to move an account is enough even without owning it.
Does Portugal recognise what I paid for a Spanish property before I moved?
It carries the original acquisition cost and date. There is no step-up on becoming resident, so the full gain since purchase is in the Portuguese base if you sell while resident here.