Even though voting is compulsory for Australian citizens aged 18 years or over, you need to be enrolled in order to vote.
If you're not on the roll by 8pm on May 23 - you won't be able to vote until 2019.
Phil Diak from the Australian Electoral Commission said the levels of enrollment overall were good, but there were concerns for younger, first time voters.
"Presently as many as half of voters aged 18, and one in four voters aged 19, are not enrolled to vote," he said.
Mr Diak said the numbers of un-enrolled voters could potentially sway the election result.
"Overall at the moment there are about 950,000 people who are missing from the electoral roll," he said.
"That is down in absolute numbers from the 2013 election, where it was 1.2 million."
What happens if I don't enrol to vote?
According to the website, the AEC sends letters to all apparent non-voters requesting that they either provide a valid and sufficient reason for failing to vote or pay a $20 penalty.
If you fail to reply or provide a valid and sufficient reason the matter may be referred to a court, where you face fines up to $170 and a possible criminal conviction.
I'm a new citizen. How do I make sure I'm enrolled?
Mr Diak said newer Australian citizens may have enrolled when they became Australian citizens and went to a citizenship ceremony.
He said there were resources available to people who needed them.
"If they're not sure they can go to the AEC website, there is information there in other languages, or you can call the AEC and you can have a three-way telephone call with an interpreter," Mr Diak said.
"It's important that all newer Australian citizens make sure that they're correctly enrolled to vote for the upcoming election, and also to take care if they have moved in recent months and they haven't updated their enrollment, they need to make sure they're correctly enrolled for their current address."
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