Australian citizenship by descent is a pathway to Australian citizenship for persons who were born outside Australia but have an Australian citizen parent. Unlike citizenship by conferral — which requires a period of lawful residence in Australia — citizenship by descent does not require the person to have ever lived in Australia. However, it is not automatic: citizenship by descent must be formally applied for and registered with the Department of Home Affairs. The legal basis is section 16 of the Australian Citizenship Act 2007. A key rule is the 20 August 1986 threshold — the date on which Australia moved from automatic citizenship by birth to citizenship by descent through a citizen parent — which affects how a parent's Australian citizenship is established when the parent was also born overseas or in Australia on or after that date.

For current application requirements, fees, and processing times, refer to the DHA citizenship by descent page.

• Australian Citizenship Act 2007, s 16 — citizenship by descent: the core provision conferring citizenship on persons born outside Australia to an Australian citizen parent
• Australian Citizenship Act 2007, s 17 — citizenship by descent for persons born to a former Australian citizen (a less common pathway)
• Australian Citizenship Amendment (Citizenship by Descent) Act 1986 — the 1986 reform that replaced automatic jus soli birth citizenship with the citizenship-by-descent framework from 20 August 1986
• DHA: Your parent was an Australian citizen when you were born — immi.homeaffairs.gov.au/citizenship-by-descent
• DHA: Confirming Australian citizenship — immi.homeaffairs.gov.au/confirming-citizenship

Core eligibility — parent was an Australian citizen at birth

The primary requirement for citizenship by descent is that at least one parent was an Australian citizen at the time of the applicant's birth. This means:

• The parent must have already been an Australian citizen when the applicant was born — a parent who became a citizen after the applicant's birth does not satisfy the requirement for citizenship by descent (though the applicant may be eligible to apply for citizenship by conferral if they then establish residence in Australia)
• Either parent can satisfy the requirement — it does not need to be both parents
• Citizenship can be traced through multiple generations (e.g., a grandparent), but the chain must be unbroken — each generation must have been a citizen at the time of the next generation's birth

The 20 August 1986 rule — establishing the parent's citizenship

Australia significantly changed its citizenship laws on 20 August 1986. Before that date, being born in Australia conferred automatic citizenship (jus soli). After that date, birth in Australia alone no longer confers citizenship — the child must have an Australian citizen parent. This change affects how the parent's citizenship is established:

Parent born in Australia before 20 August 1986

A parent born in Australia before 20 August 1986 was automatically an Australian citizen by birth. Their Australian birth certificate (showing birth in Australia before that date) establishes their citizenship status. No further documentation of the parent's citizenship status is needed — the birth certificate itself demonstrates they were a citizen at the time of the applicant's birth.

Parent born in Australia on or after 20 August 1986

A parent born in Australia on or after 20 August 1986 was not automatically an Australian citizen — birth in Australia after that date requires a citizen parent. Therefore, the applicant must demonstrate that the parent was an Australian citizen at the time of the applicant's birth, which requires showing how the parent acquired citizenship (for example, by demonstrating that the grandparent was an Australian citizen at the time of the parent's birth).

Parent born outside Australia

For a parent born outside Australia, documentation is needed to show how the parent acquired Australian citizenship (by descent, conferral, or registration) and that they held that citizenship before the applicant's birth. A parent's Australian citizenship certificate or other evidence of citizenship status is required.

Not automatic — registration required

Citizenship by descent does not arise automatically at birth. Even a person who has been eligible for citizenship by descent since birth does not become a citizen until they formally apply and are registered. Key implications:

• A person who was eligible for citizenship by descent since birth but never applied is not yet an Australian citizen — they can apply at any time, including as an adult, and there is no age limit on the application
• Until the application is approved and citizenship is registered, the person cannot obtain an Australian passport, cannot vote in Australian elections, and does not have the rights of an Australian citizen
• Citizenship by descent that has been registered is backdated — the person is treated as having been a citizen from birth

Documentation required

An application for citizenship by descent requires evidence of:

• The applicant's birth — birth certificate showing parentage
• The parent's Australian citizenship — depending on how citizenship was acquired:
  • Parent born in Australia before 20 August 1986: Australian birth certificate
  • Parent born in Australia on or after 20 August 1986: evidence of the grandparent's citizenship at the time of the parent's birth
  • Parent born outside Australia: Australian citizenship certificate or evidence of conferral/registration
• Identity documents for the applicant
• If applicable: evidence that the parent was a citizen (not a former citizen) at the time of the applicant's birth

Applications are lodged online through ImmiAccount or on paper using Form 118. For the current application guide and full documentation checklist, refer to the DHA citizenship by descent page.

Children born to a former Australian citizen

There is a separate pathway under section 17 of the Australian Citizenship Act for persons born to a former Australian citizen (a parent who held citizenship but renounced it or lost it before the applicant's birth). This is a narrower pathway with specific additional requirements. For information on this pathway, refer to the DHA child of former citizen page.

Dual citizenship

Australia permits dual (and multiple) citizenship. Acquiring Australian citizenship by descent does not require the applicant to renounce any other citizenship they hold — although the laws of the other country may affect whether they can retain both citizenships. Australia does not impose a renunciation requirement on persons acquiring citizenship by descent.

Citizenship by descent is a pathway that many Australians living abroad are unaware their children or grandchildren may be eligible for. The key practical point is that eligibility does not equal citizenship — formal registration is required. The 20 August 1986 cut-off is the most common source of complexity, particularly in cases where the citizen parent was also born in Australia on or after that date and the grandparent's citizenship must be traced. For complex lineage cases — particularly multigenerational chains or situations where the parent was born outside Australia — gathering documentation can be time-consuming, and it may be worth contacting the DHA before lodging to confirm what evidence will be accepted. For current processing times, fees, and the full application guide, refer to the DHA citizenship by descent page.