Two columns on the ballot paper, one for the firstchoice and one for the secondchoice.
First preference
First preference votes added up, if a candidate has 50% or more votes they are elected. In no candidate receives a majority, the top two are retained and the rest eliminated.
Second preference
The second preference votes of the eliminated candidates are then counted, and either of the top two candidates are added to their firstround totals. Whoever has the mostvotes after this is declared the winner.
Where
Used in mayoral elections, and Police and Crime Commissioners.