Different voting rules are already catching Wanganui voters out with a number of votes being declared invalid because they have been filled out incorrectly.
The problem has occurred with voting for the Whanganui District Health Board.
The WDHB uses the single transferable voting (STV) system which means electors must list their preferred candidates with a number rather than a tick.
But Wanganui electoral officer Noeline Moosman said yesterday that some papers had already been returned and voters had used a tick rather than a numeral for the DHB candidates.
A tick is used for the Wanganui mayoralty, district council and regional council elections. The councils use the first past the post (FPP) voting system with electors ticking the box beside the name of their preferences.