The Australian Bureau of Statistics will keep the names collected in Tuesday's Census until the end of February 2028 and the addresses until the end of August 2029, under the retention periods set out in its 2026 Census privacy statement.
That is 18 months for names and 36 months for addresses, counted from Census night on 11 August. Completing the form is compulsory, and the ABS can prosecute and fine a person who refuses after being served a notice of direction.
Both periods are shorter than what was planned a decade ago. For the 2016 Census the bureau intended to hold names and addresses for up to four years, a decision that drew sustained public objection at the time. The retention question has been revisited in every collection since.
Names are not kept for their own sake. The bureau uses them to join Census responses to other datasets, and it names the projects it uses them for.
The largest is the Person Level Integrated Data Asset, which combines Census answers with health, education, income and tax records held elsewhere in government. The Australian Census Longitudinal Dataset tracks a five per cent sample of the population across successive Censuses. A third project uses linkage to estimate Aboriginal and Torres Strait Islander life expectancy, where the count derived from separate collections has long been unreliable.
The bureau's position is that the linked data is de-identified before researchers see it, that it does not release information that could identify a person or a household to other government departments or to marketing companies, and that its staff carry lifetime secrecy obligations under law. The collection sits under the Census and Statistics Act 1905 and the Australian Bureau of Statistics Act 1975, with the Privacy Act 1988 over the top.
The secrecy provisions in that 1905 Act are the operative protection. They bind ABS officers for life, they survive the end of employment, and they are what has kept Census returns out of the hands of other agencies through every previous collection.
They are also a statutory protection rather than a structural one. What cannot be released is defined by an Act of Parliament, and an Act of Parliament is the instrument that can redefine it. The dataset that exists between now and August 2029 is the thing that would be available if that ever happened, and its size is a policy choice rather than a technical necessity.
Those are the terms of Tuesday's collection. Participation is compulsory and carries a penalty, the answers are linked to tax and health records, and the identifying data is held for a fixed period that is shorter than the one proposed in 2016.
Practical points for Tuesday. The Census counts where a person is on the night, not where they usually live. Instructions and login numbers have gone out by post since late July. Paper forms are available on request for anyone who does not want to complete it online, and the bureau has run pop-up hubs and in-language support through early August.
The retention dates are published, and they are specific. Names go at the end of February 2028. Addresses go at the end of August 2029. The collection notice setting all of that out is available now, before the form has to be filled in.
