An Australian passport is the preferred and most conclusive proof of Australian citizenship when travelling.
You will not be able to apply for an Australian passport until you have become an Australian citizen by attending an official citizenship ceremony and made the Australian Citizenship Pledge.
If you travel outside Australia before your ceremony you will be travelling as a permanent resident on your current passport. See further information about travelling before your citizenship ceremony.
Once you have become an Australian citizen any visa you held ceases.
As an Australian citizen you must always leave and enter Australia on an Australian passport. If you also have a passport from another country you can use that for travel once you have left Australia.
People trying to enter Australia as an Australian citizen but without an Australian passport face difficulties and delays. The Australian Passport Office provides more information.
If you also have a passport from another country you should always use your Australian passport when leaving and entering Australia.
Travel after Australian citizenship has ceased
If you renounce your Australian citizenship while overseas you cannot re-enter Australia without a valid visa.
You will automatically become the holder of an ex-citizen visa if you renounce your Australian citizenship while in Australia. This visa allows you to remain in Australia but does not allow you to re-enter Australia should you leave.
You will need a Resident Return Visa if you travel overseas and intend to return to Australia.