Main source of personal income (administrative data) (ISAP)

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Census of Population and Housing: Census dictionary
Reference period


This variable indicates the main source of income that a person received based on all income recorded in administrative data for the 2020/2021 financial year. 

This variable wasn’t derived from data collected on the Census form but has been created by linking administrative data from the Person Level Integrated Data Asset (PLIDA) to the Census. 


Persons aged 15 years and over


0Nil or negative income
1Employee wages and salary
2Government benefits and allowances
3Own unincorporated business income
4Superannuation income
5Investment income
6Other income
9Admin not available
@Not applicable
VOverseas visitor 

Number of categories: 10

Admin not available (9) category comprises:

  • Persons who were not able to be linked to PLIDA, and therefore did not have administrative income information available

Not applicable (@) category comprises:

  • Persons aged under 15 years

How this variable is created

This variable wasn’t derived from data collected on the Census form but has been created by linking administrative data from the Person Level Integrated Data Asset (PLIDA) to the Census. The PLIDA data asset contains administrative income data from the Australian Taxation Office and the Department of Social Services, this is the source data for this variable. 

The main source of income is the category with the largest total income recorded between 1 July 2020 and 30 June 2021. This variable does not record the dollar amount of income earned; it records what the main source of income is.  

For example, a person may have earned substantial income from a salary and received a small amount of additional income from investments. This variable only records the main source of their income, in this case a salary.  

In the case of a person receiving the same amount of income from two or more sources, the main source of income was selected by choosing the income type which was higher in the following ranked list: 

  1. Employee wages and salary 
  2. Government benefits and allowances 
  3. Own unincorporated business income 
  4. Superannuation income 
  5. Investment income 
  6. Other income 

History and changes

This is a new variable for 2021.

Data use considerations

This variable provides an alternative, more detailed view on income than income data collected in the Census. It is based on income information recorded in linked administrative data, and not data collected from a Census question. 

Comparison to other ABS Surveys 

Although other ABS surveys, such as the Survey of Income and Housing and Person Income in Australia, collect similar data relating to personal income, they are not directly comparable. This is due to differences in scope, collection methodology, the time period the collection relates to, and conceptual differences. It is likely that data from each of these collections will deliver different outcomes making it important for data users to understand the key conceptual differences between each collection to use it most appropriately. 

Financial Year income as a measure of usual income 

Financial Year income from the administrative data is used to measure the main source of income. The Financial Year captures longer term trends of income and is not subject to short term changes around Census time. This means that this variable may not align with what a person earned, or usually earned around the time of the Census. 

Superannuation income in administrative data 

The administrative data used to derive this variable had limited coverage of income from superannuation, because many superannuation payments are not required to be reported annually to the Australian Taxation Office.  

This means that we have under-recorded the amount of income people received from superannuation. In these cases, the main source of personal income would either be set to another income type (where the person also received income from another source) or income for this person would be incorrectly set to Nil.  

This has resulted in a known undercount of the number of people with superannuation as their main source of personal income, and an overcount of the number of people with other income types as their main source of personal income.   

Linkage rates between Census and administrative data 

This variable relies upon the accurate linkage of Census to the administrative data. Data linkage rates (denoted through the 99 and 9999 categories) need to be considered in conjunction with the administrative income when assessing totals.  


A number of regions across the country were in various stages of lockdown due to the COVID-19 pandemic throughout the 2020/2021 Financial Year. This resulted in a greater number of people being temporarily stood down, which impacted the main source of income recorded in administrative data. 

Related variables and glossary terms

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