Enter the GROSS income, before the foreign withholding: that is what Portuguese tax is charged on (art. 22.º, n.º 6). Confirm the treaty cap in the tax authority's summary table of treaties; 15% is the most common cap on dividends paid to an individual.

€150.00 was withheld above what the treaty allowed. With a 15% cap, the treaty only authorised the source country to charge €150.00, and Portugal credits only up to that amount (art. 81.º, n.º 2). That excess is not claimed from the Portuguese tax authority: it is claimed from the tax authority of the country that withheld it, normally by proving Portuguese tax residence. If it is not claimed, it is lost.

Without the credit you would pay €580.00 of tax on this income, here and abroad. The credit is worth €150.00.

One income, from one country, in euros. Not computed: currency conversion (each amount at the rate of its own operation date), the rest of the taxpayer's IRS, the 50% inclusion of Portuguese and EU dividends under englobamento (art. 40.º-A, which has its own calculator), the amount of the five-year carry-forward, the exemption method for IFICI beneficiaries (art. 81.º, n.º 4) and the treaties that give the credit to the source state (n.º 10).

Informative estimate based on the Portuguese income tax code. Not tax or financial advice.