The purpose of the issue of an Australian Visa is to to provide a legitimate document to stay or transit through Australia.

There are different types of Australian Visa according to the format of the travel and purpose. All foreigners with the exception of citizens of New Zealand and Norfolk islands are required to obtain an Australian visa if they want to stay or transit through Australia.

An Electronic Transit authority or ETA is issued for visits with duration of less than three months. ETA is mostly availed by tourists who are visiting Australia en route to other destinations. If the person is halting for more than 72 hours in Australia during the course of his travel he would require to obtain a Visa. Transit visa are regularly issued by the immigration authorities and no fee is charged and is issued instantly. However if you want to break your journey en route to another destination for the purpose of sight seeing in Australia you will need a visitors visa. If you do not have proper travel documents which include visa, passport or ETA you could be refused entry into the aircraft by the aviation officials.

All persons  are required to obtain a Australian Visa if they want to visit or transit Australia.

An application is deemed valid until it is from a specified class, all the prescribed fees have been paid and the application is made in the approved form.

The rules can be altered under special circumstances like Birth of a child in the intervening period between applying and granting of visa or in the case of non Citizens applying but unsuccessful for a substantive visa are regarded as applied for Bridging D Visa. A visa  can be approved in the case of  an Australian citizen were to nominate a non-citizen desiring to visit Australia for business purpose. The person will be issued a Temporary Business Entry Australian Visa for the period required for completing the business deal. One last detail which should be noted is if you are found in Australia without a proper visa, you may not be allowed to stay in Australia and your future requests for a visa is likely to be denied.

The time required to process a visa can vary according to your country of origin, the category of the Visa or the filling of the required details in the application. Your visa application can be delayed due to one or many of the following causes:
•    Details filled wrongly in the application form
•    Improper interpretation of visa requirements
•    Personal interview for further clarifications by the immigration authorities
•    Ill health of the applicant or carrier of contiguous diseases
•    Person facing criminal proceedings in the country of origin
•    Supporting documents erroneous or wanting
•    Request for additional documents
•    Workload on the immigration section

Therefore before applying for an Australian visa it will be prudent to thoroughly check if you fulfil all the criteria for getting a visa. If you have all your papers in order you can rest assured that the processing of your application will not take much time.