If you are tax resident in Portugal, Portugal taxes your worldwide income and then relieves the double taxation. Two mechanisms do that work, they produce different answers, and which one applies is not your choice.
The credit method
The ordinary relief is a credit against Portuguese tax — and the amount is the lesser of two figures, not simply the tax you paid abroad.
- The tax actually paid in the source country, and
- The fraction of the Portuguese collecta attributable to that income.
The treaty cap, and what to do about it
Where a treaty applies, the credit is further capped at the treaty rate — not at whatever was actually withheld. If the payer withheld more than the treaty allows, the excess is not Portugal's to give back: it is reclaimed from the source country.
| Income | Cap |
|---|---|
| Dividends | 15% |
| Interest | 10% |
| Royalties | 10% |
Unused credit carries five years
Where the credit cannot be used in the year, it can be carried forward for five years — so a bad year is not necessarily a lost credit.
Exemption with progression
The other mechanism does not tax the foreign income at all — but it still counts. The income is aggregated for the purpose of setting the rate, and the rate is then applied to the rest. Exempt income raises the rate on everything else.
This is how foreign income works under the IFICI regime: categories A, B, E, F and G are exempt with progression rather than untaxed in the way people usually mean.
The foreign-account box
Separate from income, and the obligation people miss: foreign accounts are declared in quadro 11 of the Modelo 3 folha de rosto. There is no income threshold — an account that earned nothing is still declared.
- An account that earned nothing is still declared.
- Being a signatory on an account is enough — you need not own it.
- A foreign branch of a Portuguese bank counts as foreign.
Omission carries a penalty under RGIT art. 119, with the limits reduced to a quarter where no tax was due — which tells you the obligation is about visibility rather than revenue, and that a nil account is exactly the case the rule expects you to declare.
Arriving and leaving
| Event | Effect |
|---|---|
| Becoming resident | Residence starts on the first day of the stay |
| Ceasing residence | Residence ends on the last day of presence |
The 183-day test itself is the well-known part. The rules around the edges of it are what decide the outcome for anyone actually moving.
How does Portugal avoid double taxation on foreign income?
Usually by credit: the relief is the lesser of the tax actually paid abroad and the fraction of the Portuguese collecta attributable to that income. Where a treaty applies, the credit is capped at the treaty rate. Some income is instead exempt with progression, meaning it is not taxed but still counts towards the rate on everything else.
What if the foreign country taxed me more than Portugal would?
The excess is not credited. The credit stops at what Portugal would have charged on that income.
What if too much was withheld abroad?
Portugal credits only up to the treaty rate. Over-withholding above that is reclaimed from the source country, not from Portugal.
Can unused foreign tax credit be carried forward?
Yes, for five years.
Do I have to declare a foreign bank account with no income?
Yes. Foreign accounts go in quadro 11 of the Modelo 3 folha de rosto with no income threshold — and being a signatory is enough, even without ownership. A foreign branch of a Portuguese bank counts as foreign.
Does exempt foreign income affect my Portuguese tax?
Yes, where the exemption is with progression. The income is not taxed but is aggregated to set the rate applied to your other income.
When does Portuguese tax residence start and end?
It starts on the first day of the stay and ends on the last day of presence. Where you were resident on any day of the previous year, it backdates to 1 January instead.