To remain longer in Australia than your original visa allows, you are required to have another visa. If you want to extend your stay for tourism or recreational purposes or to visit family or friends, you may apply for a Tourist visa.
Generally, as a holder of a Working Holiday visa or Visitor visa you can only extend your stay in Australia so that the total duration of your stay is 12 months or less, unless there are exceptional circumstances. If you hold a Visitor or Working Holiday visa which allows you to stay in Australia for 12 months, you should contact your nearest Australian visa office before applying for a Tourist visa.
It is recommended that you apply for a new visa at least two weeks before your current visa expires. You should also note that a further visa, if granted, will cease any visa or ETA currently held and the entitlements attached to that visa or ETA.
If you are refused a further visa, you must leave Australia before the expiry of your authorized stay period.