There are many different types of voting systems in use around the world. Some of the most commonly used are described below.

First past the post

The first past the post system is the simplest method of voting – the candidate who polls the highest number of votes is elected. This system is easy to understand and the result of the election may be quickly determined.

It can be used in elections for one or more vacancies.

The elector marks his/her vote on the ballot paper by placing a tick or a cross in the square opposite the names of a number of candidates, not more than the number required to be elected.

The system is criticised because the candidate(s) elected may not be preferred by the majority of electors. Candidates can be elected with less than 50% of the formal vote. In an election where two or more factions contest the election, it is also possible that one faction will fill all vacant seats.

Preferential voting

The object of preferential voting is to ensure that the candidate(s) most preferred by the voters are elected to fill the vacancies. A candidate must receive an absolute majority of votes (more than 50%) to be elected.

The major disadvantages of any preferential system are:

  • The percentage of informal votes is generally higher, and
  • Electors may be required to express preferences for unknown candidates.

There are a range of systems to conduct elections using preferential voting.

Preferential voting to fill one vacancy

An elector must mark the ballot paper by placing the number 1 in the square opposite the name of the most preferred candidate and the numbers 2, 3, 4 and so on in the squares opposite the names of remaining candidates.

In a full preferential system the voter must allocate a number to every candidate. In an optional preferential system the voter is only required to mark at least one first preference and may mark further preferences. Partial preferences may be required if the number of preferences marked must equal a specified minimum or at least the number of vacancies to be filled.

A candidate must receive an absolute majority (more than 50%) of the formal votes to be elected under this system.  Where no candidate has an absolute majority, the candidate who has the lowest number of votes is excluded from the count and his/her ballot papers are transferred to the candidate next in order of the voter’s choice as indicated on the ballot papers. The process of excluding candidates and transferring ballot papers continues until one candidate has an absolute majority.

In the Northern Territory full preferential voting is used in:

  • Federal elections for the House of Representatives, and

  • Legislative Assembly elections.

Exhaustive preferential for more than one vacancy

This system is very similar to the preferential voting system to fill one vacancy as described above. The ballot paper is completed in the same way and the process to fill the first vacancy is the same.

The second vacancy is filled by re-sorting all ballot papers to their first preference. The first elected candidate is then excluded and his/her votes are transferred to the candidate next in order of the voter’s choice. All votes have a value of 1. If no candidate has an absolute majority, the process of excluding candidates and transferring ballot papers continues until one candidate has an absolute majority. This process then continues until all vacancies are filled.

This vote counting system was used in Northern Territory local government elections until 2012.

Bottoms-up preferential for more than one vacancy

Electors mark their ballot paper in the same way as for the preferential voting system to fill one vacancy, as described above.

The candidate who has the lowest number of votes is excluded from the count and the ballot papers are transferred to the candidate next in order of the voter’s choice. The process of excluding candidates and transferring ballot papers continues until the number of candidates remaining in the count equals the number of vacancies to be filled.

The advantage of the bottoms-up preferential system over the exhaustive preferential system is that there is a lower probability that one faction would fill all vacancies.

Proportional representation for more than one vacancy

Candidates are elected in proportion to the number of votes they poll. Generally, proportional representation (PR) is used in elections for more than one vacancy. It is more complex than other systems and results may take longer to finalise.

An elector must mark the ballot paper by placing the number 1 in the square opposite the name of the most preferred candidate and the numbers 2, 3, 4 and so on in the squares opposite the names of remaining candidates.  The elector may be required to express a preference for all candidates or may be required to express a preference for a certain number of candidates, usually for at least the number required to be elected.

Candidates are elected when they have reached a quota, that is, a predetermined proportion or percentage of the total number of formal votes cast.

Any candidate who polls a number of votes equal to or greater than the quota is elected. Any votes above the quota are transferred to the candidate next in order of the voter’s choice at a fraction of their value (known as the transfer value). The transfer value is determined by dividing the number of votes above the quota (the surplus) by the total number of votes polled by the candidate. If vacancies remain unfilled, the candidate with the fewest votes is excluded from the count and all ballot papers held by the excluded candidate are distributed to the remaining candidates. The ballot papers are transferred at the transfer value they were received by the excluded candidate.  This process is repeated until all vacancies are filled.

The system allows the involvement of groups in the electoral process and ensures that their representation is in proportion to the number of votes received. That is, if a group obtains 20% of the formal vote they are likely to fill 20% of the vacant seats.

This system is used in elections for the Australian Senate and NT Council Elections.

For explanations of the PR vote counting system used in NT Council Elections, see the following three information sheets and booklet:

More information

More information on voting systems can be found on the following sites: