Just four days from Victoria's election, the state's preferencing system continues to confuse voters.

The Victorian Electoral Commission admitted it has been running sessions with communities to educate people on how to cast a formal vote.

Electoral Commissioner Warwick Gately has tried to explain the importance of properly completing ballot papers for the upper and lower houses.

"The lower house ballot is a full preferential vote, meaning you need to number every box in the order of your preference," he said.

In the upper house, it takes just one number above the line or a number in every box below the line.

Upper house MP Fiona Patten has vowed to initiate reform of the state's preferences system if re-elected.

She has made claims, being investigated by police, that parties are charging charging money to form preference deals.

"My first priority as a member of the next parliament will be to initiate reform of the voting system in Victoria as well as changes to the Electoral Act to make it an offence to trade in votes or preferences or in any way make a profit from the democratic processes," Patten said.

There is expected to be a late start to campaigning on Tuesday as leaders from both major parties attend the state funeral for terror stabbing victim, Sisto Malaspina.