Chief electoral officer Taggy Tangimetua said there were a number of voters who were eligible to vote via the postal and advance voting.
Postal voting is given to any registered elector currently outside of the Cook Islands and will not be in the constituency on election day.
This made up two per cent of the total votes counted in the 2014 elections.
Most of these postal votes in the last elections were from students studying overseas and those who were away for medical reasons or for a period of less than three months.
Of the total votes posted in 2014 elections, only 57 per cent were returned and the Elections Office is hoping for a better response in this year’s elections.
In advance voting, electors, who were unlikely to be in their constituency for whatever reason on election day, are allowed to vote before the actual election.
“We have started votes in advance and postal voting. People who are leaving the country and will not be here on the election day can visit the Elections Office from 9am to 1pm on the working days to cast their vote,” Tangimetua said.
“There are also a number of voters who are eligible for postal voting.
They have listed their postal contacts in their registration and we are working on posting the ballot papers to these addresses.”
The other three voting methods are special voting (declaration), special care and ordinary voting.
Special voting or vote by declaration is for those electors who since the closing of the rolls have become qualified - turned 18 years of age; or spent three months in the constituency but did not register or simply forgot to register or change their elector details.
Special care voting is for those electors who are unable to attend the booth due to illness or disability.
An ordinary vote is the simplest way to vote at the polling booth for those whose names appear on the electoral roll. This the method used by most electors.
The 2018 elections will see 58 candidates contesting under the banner of Cook Islands Party, Democratic Party, One Cook Islands (OCI), Independent, Titikaveka Oire and Alternative Must Ravenga Openga for 24 seats.