Sources and method
Every fact on a page comes from the Autoridade Tributária e Aduaneira (AT), Portal das Finanças, and is dated on the page.
Where the data come from
- The AT page "Convenções e Quadro Resumo das Convenções" lists one official document per convention. On the day we read it, it said that Portugal has 79 conventions, of which 78 are in force and 1 is signed and awaits entry into force. We link the official instrument from that list.
- The AT "Quadro resumo das convenções 2026" gives, for each country, the legal instrument, the Aviso and its publication date, and the date of entry into force. We quote these texts as printed and read the dates from them by code. The table also lists Finland and Sweden, whose conventions ceased to apply, and Kenya, whose convention is signed but not yet in force.
What we leave out
We do not show withholding tax rates: in the AT table they carry conditions, and we show a figure only when we have read it from the convention text itself. A field the sources do not give is left out. A country without a convention on the AT list has no page.
The AT texts are in Portuguese and are quoted as printed. The English labels are ours. This site does not give legal or tax advice: the Autoridade Tributária e Aduaneira and the convention text decide.