Non-citizens in Australia without a current visa are unlawful and must, by law, be detained. Bridging visas provide lawful status in the following situations to non-citizens who would otherwise be unlawful:
Bridging visas A: for applicants who hold a substantive visa when they apply for another substantive visa.
Bridging visas B: (the travel visa) for those who have a bridging visa A (or existing bridging visa B) and have valid reasons for traveling overseas during processing of their substantive visa application.
Bridging visas C: for applicants who do not hold a substantive visa, have made a valid application in Australia for a substantive visa, and have not been located by the Department of Immigration and Multicultural Affairs.
Bridging visas D: for a non-citizen who is unlawful (or will become unlawful within three working days) and wishes to make a substantive application but is unable to do so. Or an unlawful non-citizen unable or not intending to make a substantive application and an authorised officer is not available to interview them for the purpose of considering their eligibility for a bridging visa E.
Bridging visas E: for those who are unlawful and have been located by DIMA, have been previously granted a bridging visa E, or are a bridging visa D holder.