As 38,000 collectors across Australia prepare for the enormous task of undertaking the Census of Population and Housing on August 9, the Australian Bureau of Statistics in Canberra will shoulder more of the processing than ever before.

Chris Libreri, general manager of the Census and Statistical Network Services Division, said the ABS in Belconnen will hold the data processing centre that was previously based in Sydney or Melbourne.

"We will be employing about 500 Canberrans who will be working here in Belconnen processing the census," he said.

"We always have a national processing centre but for the first time ever that is here in Belconnen."

The census is carried out every every five years, and is the most comprehensive source of information about Australia's population.

Information collected helps to determine where taxpayers' money will be spent in areas such as health, education, transport and infrastructure.

Data from the 2011 Census showed that Australians came from more than 200 countries, spoke more than 300 languages, belonged to more than 100 religious groups and worked more than 1,000 different jobs, the ABS reports.

Mr Libreri said the logistics of taking the country's temperature on such a wide range of topics was complex.

"We think it is the biggest peacetime operation in Australia," he said.

"It takes years of planning and we have about 21 different special strategies to collect the data, but we have made the process much more efficient with considerably less field activity and gathering more data electronically."

He hoped about 65 per cent of people would complete this year's census online, which was more than twice as many from the last census and six times more than in 2006, when the digital option was first introduced.

But of course, not everyone will have an internet connection handy.

And those who'll be in the middle of the ocean or backpacking through the outback will be hard to track down at all.

Mr Libreri said collectors will visit remote areas such as truck stops and caravan parks to ensure every person in Australia participates in the compulsory survey.

"We also have a homeless strategy where we work with non-government services such as Vinnies [St Vincent de Paul Society] to find the people they work with, as well as visiting known places where homeless people spend the night," he said.

"We even have special operations for oil wells, mining operations, cruise ships, secure apartment buildings, all the different types of places where people are going to be on census night."

Obviously this scale of work requires a lot of time and money.

Mr Libreri estimated it would cost tax-payers $400 million, but he stressed its necessity.

"Lots and lots of critical decisions are based on the census and population data that is derived," he said

"The GST formula is based on that, our electoral boundaries are based on census data and population data, and it is also used by businesses looking to expand or locations."

When asked if the process could be done more efficiently by joining the ABS with another agency so data sources could be combined and analysed more regularly, he said the bureau already worked closely with other agencies.

And it also works very closely with the personal data it collects.

Its plans to retain names and addresses has attracted criticism from some privacy experts, including a former Australian statistician, Bill McLennan, who says it is "without doubt the most significant invasion of privacy ever perpetrated on Australians by the ABS".

Mr Libreri said people's privacy would be strictly protected with a range of measures, including by "ethical hackers" employed to give security tips.