The legitimacy of local authority decisions results from the election of the respective bodies, which are constitutionally enshrined as:
- Executive bodies - the town council and the parish council, i.e., these are the bodies which, in practical terms, are responsible for proposing and implementing the decisions and indications of the deliberative bodies.
- Deliberative bodies - the municipal assembly and the parish assembly, which have the responsibility for approving or not, among other powers of their own initiative, the proposals of the respective executive bodies.
Local authority bodies are elected by direct universal suffrage, except for the parish council, whose president is the citizen who headed the list with the most votes in the election to the parish assembly. The other members of the executive are elected at the first meeting of the parish assembly, on a proposal from the president.
Votes are converted into seats in accordance with the proportional representation system and the Hondt method. The number of deputies for each constituency is proportional to the number of citizens registered in it.
The mandate of local authority officeholders is for 4 years. Since 2005, a limit of 3 consecutive mandates has been legally established for the presidents of executive bodies (mayors of municipal councils and parish councils).
The following are eligible for local elections:
- Portuguese citizens voters.
- Citizens who are voters of Member States of the European Union when they have the same right as Portuguese citizens in the State of origin of those Member States.
- Citizens electing Portuguese-speaking countries who have resided in Portugal for more than four years, when Portuguese citizens are legally entitled to the same right in their State of origin.
- Other citizens voters with legal residence in Portugal for more than five years, if nationals of countries that, under conditions of reciprocity, assign passive electoral capacity to the Portuguese living in them.
The lists of countries whose citizens are recognized as having passive electoral ability are published in the Diário da República. With the publication of Declaration 29/2021, of March 17, Portugal made public the recognition of the passive electoral capacity of the natural citizens of the Member States of the European Union, Brazil, Cape Verde, and the United Kingdom, in the elections for the organs of local authorities.
They shall have active electoral ability, i.e., they may exercise their right to vote in local elections:
- Portuguese citizens.
- Citizens of the Member States of the European Union when of equal right legally enjoy the Portuguese citizens in the State of origin of those.
- Citizens of Portuguese-speaking countries with legal residence for more than two years, when of equal right legally enjoy the Portuguese citizens in their State of origin.
- Other citizens with legal residence in Portugal for more than three years, if nationals of countries that, under conditions of reciprocity, attribute active electoral capacity to the Portuguese residents in them.
The lists of countries whose citizens are recognized as having passive electoral ability are published in the Diário da República. With the publication of Declaration 29/2021, of March 17, Portugal has made public the recognition of active electoral capacity to citizens of the Member States of the European Union, Brazil, and Cape Verde, as well as Argentina, Chile, Colombia, Iceland, Norway, New Zealand, Peru, United Kingdom, Uruguay and Venezuela, in the elections for the organs of local authorities.