For corporate tax purposes, companies and other taxable entities are deemed to be resident if they have in Portugal their legal seat (sede) or their place of effective management (direcção efectiva). The main consequence deriving from the qualification of an entity as a tax resident under Portuguese law is that such an entity becomes liable to be taxed in Portugal on its worldwide income.

Effective 1 January 2021, a non-resident entity that does not have any headquarters nor any place of effective management or a permanent establishment in Portugal but which derives income from Portugal is required to appoint a natural or legal person who is resident in Portugal or having headquarters or place of effective management in Portugal as a tax representative for complying with their tax obligations.