Campaign to explain 2021 Census begins

From Sunday, advertising will run on television, radio, print, digital and social media to explain Australia's 18th Census.

This year households will have several days to complete the Census, rather than a single night.

The advertising encourages people to start their Census as soon as they receive instructions if they know where they'll be on Tuesday, August 10.

"We know people expect flexibility and convenience, so this makes it easier for people to fill in their form when it best suits them," Australian Statistician David Gruen said in a statement on Sunday.

"I encourage everyone to participate in the 2021 Census and help build a better future for all of us."

Dr Gruen said the Census data provides a snapshot of the nation and important information about Australia's economic, social and cultural make-up.

"The Census is fundamental to helping us as a nation plan for our future," Assistant Treasurer Michael Sukkar said in a statement.

"Census data underpins a broad range of government, business and community decisions from major policy and expenditure to local services across infrastructure, health, education and transport."

The data is also used for planning electoral boundaries, federal government grant allocation and GST distribution.

Australian Associated Press