Compulsory voting
Countries that have compulsory voting by law but do not enforce it:Although voting in a country may be compulsory, penalties for failing to vote are not always strictly enforced. In Australia and Brazil, providing a legitimate reason for not voting (such as illness) is accepted. In Argentina, those who were ill on voting day are excused by requesting a doctor to prove their condition; those over away from their voting place are also excused by asking for a certificate at a police station near where they are. Belgian voters can vote in an embassy if they are abroad or can empower another voter to cast the vote in their name; the voter must give a "permission to vote" and carry a copy of the eID card and their own on the actual elections.
Voting age
A voting age is a minimum age established by law that a person must attain before they become eligible to vote in a public election. Today, the most common voting age is 18 years; however, voting ages as low as 16 and as high as 25 currently exist (see list below). Most countries have set a minimum voting age, often set in their constitution. In a number of countries voting is compulsory for those eligible to vote, while in most it is optional.