Preferential Voting in Single Member Electorates - Western Australia

Electoral Authority: Western Australian Electoral Commission
Parliament which uses Preferential Voting Legislative Assembly (Lower House)
Name of Preferential Voting system Full preferential
Formality/Informality points Formal

A formal ballot paper clearly indicates the elector's intention with respect to the order of preference for all candidates, i.e. all squares have been numbered consecutively.

A ballot paper may still be considered formal where:

  • A ballot paper has only two candidates, and only one square is marked showing a clear preference for the elector's preferred candidate.
  • A ballot paper that has been completed but not numbered consecutively, i.e. a number has been repeated or omitted, as the preferences can be distributed until the point of the error, where the vote becomes exhausted.


A ballot paper is informal if it:

  • is blank
  • does not show preferences according to the instructions
  • does not make the voter's intention clear or
  • is marked in a way that identifies the voter.
Directions on the Ballot Paper Number the boxes from 1 to N in the order of your choice. Remember… Number every box to make your vote count

*N refers to the total number of candidates.
Casual Vacancies A casual vacancy is filled through a by-election.

Related Western Australian electoral information