Electoral commissioner, Tom Rogers, said anyone who already has their postal voting pack should complete their ballot papers and return them as soon as possible.

"As of COB Friday, we'd received more than 1.3 million postal vote applications, processed them and dispatched ballot papers to voters," Mr Rogers said.

"While you have until election day to complete your ballot papers, don't wait until the last minute - complete your postal vote and send it back to us as soon as possible."

Australians voting via post must correctly complete their ballot papers, seal them inside the envelope provided, sign that envelope and have it witnessed before the close of polling on election day, this Saturday, May 18.

"Both your Senate and House of Representatives ballot papers must be returned to the AEC, sealed inside the envelope provided, for your vote to count," Mr Rogers said.

It could already be too late to apply for some

While applications for postal votes can be lodged with the AEC until 6pm on Wednesday,

Mr Rogers cautioned that time was running out.

"If you need a postal vote, please don't leave it to the very last minute," he said.

"For some locations, applications left until the last minute creates the risk that we just simply can't get ballot papers to you, despite our best efforts, and you might need to consider the option of an early vote in person rather than postal voting."

An early polling site for Great Lakes voters at 50 Wharf Street will remain open until 6pm this Friday, May 17.

The site opens from 8.30am, and remains open until 6am, except Thursday, which closes at 5.30pm.