Factbox: How to enrol to vote

Julia Gillard has called an election for August 21, and has indicated new voters have only until 8pm on Monday to get on the electoral roll.

First time voters must enrol to vote before they are eligible to cast their ballot on Election Day.

Any Australian citizen over the age of 18 is eligible to vote.

In order to be on the electoral roll, you must fill in an enrolment form.

Enrolment forms can be found on the Australian Electoral Commission's website.It is important to note that you can not update your electoral details by phone or email.

If you do not have access to the internet, or are unable to download the form, you can pick up paper enrolment forms from the following places:

- Australia Post outlets

- Any Australian Electoral Commission (AEC) office

- Tax Office shopfronts

- Centrelink customer centres

- Medicare offices

- Some Rural Transaction Centres

Once you've filled out the form, you must sign it and get someone to witness it. All signatures must be handwritten, or will not be accepted.

After the form has been signed and witnessed, it must be mailed or faxed to the AEC. Some types of forms can be scanned and emailed to the AEC.

First-time voters only have until 8pm the day an election writ is issued to join the electoral roll. A writ is a document issued by the federal government and signed by the Governor-General that orders the holding of an election for political office. These are usually issued on the same day an election is called.

You must also fill in an enrolment form if you have recently changed your residential address.

You have three working days after a writ for an election has been issued to update your existing electoral roll details.

You will receive a confirmation letter from the AEC once your enrolment form has been received and processed. You can also check your enrolment details online.