Australia is a sovereign country and has the right to decide who can enter and stay on its territory. Only Australian citizens have the unrestricted right to travel freely in and out of the country. All other people must have an authority, in the form of a visa, to enter and stay in Australia. In some circumstances a visa to enter / stay in Australia may be cancelled. Visa cancellation can mean detention and removal from Australia.
A visa may be cancelled when:

• the holder fails to comply with the conditions of their visa, for example:
  • working while holding a visitor visa; or
  • not meeting course requirements while holding a student visa; or
  • working for more than three months for one employer as a Working Holiday maker;

• circumstances under which the visa was granted no longer exist, for example:
  • holders of a spouse / fiancee temporary visa where the relationship with the Australian sponsor breaks down, or
  • a long stay business visa holder who no longer works for his sponsor;

• the holder fails the character test, for example:
  • when the person has a substantial criminal record ; or
  • when the person either has, or has had, an association with an individual, group or organisation suspected of having been, or being, involved in criminal conduct; or
  • when, having regard to the person's past and present criminal / general conduct, the person is found not to be of good character;

• other prescribed circumstances, for example:
  • where incorrect information or bogus material has been provided on an application form, including answers on passenger cards; or
  • holder of the visa is a person whose presence in Australia is, or would be, prejudicial to relations between Australia and a foreign country;

A person, whose visa is cancelled for failure to comply with visa conditions, may experience difficulty in obtaining a visa if they attempt to return to Australia.
A person, whose visa is cancelled because they fail the character test on the grounds of either a substantial criminal record, or past and present criminal conduct, is permanently excluded from Australia.
See also:
Fact sheet 79 The Character Requirement

        Where the decision to cancel a visa on character grounds is made by the Minister personally, the person has no right of appeal to the Administrative Appeals Tribunal (AAT).
Where a delegate of the Minister (usually an officer of the Department) cancels the visa and the person is in Australia they will, in most cases, have a right to have the decision reviewed by the AAT.
When a person is notified of a decision to cancel a visa they will be advised of their rights to seek a review of the decision. Strict time limits apply on appeals to the AAT. Applicants seeking reviews of decisions must apply to the AAT within nine days of being notified of the decision.
In cases where there is no power for the AAT to review the merits of a case an applicant may seek judicial review of the legality of the decision.