Child type (sex recorded at birth of parent) (including grandchildren) (CTGP)

Latest release
Census of Population and Housing: Census dictionary
Reference period
2026

Definition

This variable records the different types of children in a family, including grandchildren. When a step parent and child relationship is identified, it also shows the sex recorded at birth of the step parent.  

This variable is different from the standard child type (sex recorded at birth of parent) (CTPP) variable, as it contains an additional category for ‘Grandchild’. The ‘Grandchild’ category includes grandchildren of any age who don’t live with a natural, adopted, step or foster parent. This is different from the CTPP variable, which only includes grandchildren aged under 15 years in the 'Otherwise related child (under 15 years)' category.  

This variable can only be used with other grandparent or grandchild variables: 

It cannot be used with standard family variables. 

Scope

All children and grandchildren present in family households on Census night

Categories

CodeCategory
1 Natural or adopted child of both parents or lone parent 
2 Step child of parent, sex male 
3 Step child of parent, sex female 
4 Foster child, so stated 
5 Grandchild 
6 Otherwise related child (under 15 years) 
7 Unrelated child (under 15 years) 
@ Not applicable 
V Overseas visitor 

Number of categories: 9 

Not applicable (@) category comprises: 

  • husbands, wives, spouses, partners, lone parents, other related individuals, non-family members, or visitors (from within Australia) in family households 
  • persons in non-family households 
  • persons in non-classifiable households 
  • persons in non-private dwellings 
  • persons in migratory, offshore and shipping SA1s 

See Understanding supplementary codes for more information. 

Question(s) from the Census form

What is the person’s date of birth and age?

What was the person’s sex recorded at birth?

What is the person’s relationship to person 1/person 2?

Is the person attending a school or other education institution?

For each person away, complete the following questions:

How this variable is created

This variable is created using responses to the relationship in household, age, attendance at an educational institution and persons temporarily absent (PTA) questions on the Census form. It is derived from the relationship in household (including grandchildren) (RLGP) variable. 

A person is classified as a grandchild, regardless of age, if they are classified as one of the following RLGP categories: 

  • 34 Grandchild under 15 years 
  • 44 Dependent full-time student grandchild (15-24 years)
  • 54 Non-dependent grandchild 15 years and over

Child type (including grandchildren) (CTGP) is different from the standard child type (CTPP) variable.  

History and changes

This variable was created in 2011. 

In 2026, updates were made to the variable name and categories to align with updated wording of questions on the form.  

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