Vendors of banking and insurance services are struggling to reach almost 18 per cent of the population,
research by the Centre for Social Impact suggests.
The centre released updated research yesterday that shows that more than three million Australians don't have access to a basic transaction account or a moderate amount of credit, or don't have general insurance. The centre last produced data on the topic two years ago.
National Australia Bank helped fund the study, which draws on the database of Roy Morgan Research.
Around 17.7 per cent of the adult population in Australia were either fully excluded or severely excluded from financial services in 2012, the CSI said.
This comprises 1.1 per cent of adults who were fully excluded (meaning they had no financial services products), while 16.6 per cent were severely excluded (meaning they only had one financial services product).
This CSI said this represents an increase from the previous report, based on 2011 data, which identified 17.2 per cent of the population as being either fully excluded or severely excluded.
The centre estimated that 194,000 adults are fully excluded and 2.9 million are severely excluded.
The centre also estimates the average annual cost of basic financial services to be A$1739.
This is made up of $85 for a basic bank account, $711 for a low cost credit card, and $943 for general insurance (basic motor vehicle and home contents combined).
For 9.2 per cent of the population this would represent over 15 per cent of their annual income, the centre said. For another 9.1 per cent of the population this would represent between 10 and 15 per cent of their annual income.
Chris Connolly, research associate at CSI, said his best explanation for the rise in exclusion was "there's a bit of a lag between a change in economic conditions and the [financial] crisis.
"The reason for the lag is that, if you have a bank account or insurance, you do your best, even if circumstances change, to hold on as long as you can. In a couple of years you give up.
"Then new people come in - those leaving school, new migrants.
"I think it'll be a really stubborn problem and [it will] be very difficult to get the figures to go back down."