Child type (sex recorded at birth of parent) (CTPP)

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

Definition

This variable records the different child types in a family. If a step parent and child relationship is recorded, it also shows the step parent’s sex recorded at birth. 

Scope

All children 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 Otherwise related child (under 15 years) 
6 Unrelated child (under 15 years) 
@ Not applicable 
V Overseas visitor 

Number of categories: 8 

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 any 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.  

Children aged under 15 years are classified as: 

  • a child if they live with a natural, adoptive, step or foster parent 
  • an ‘Otherwise related child (under 15 years)’ if they live with an adult relative (such as an older sibling, aunt, uncle, or grandparent) and no natural, adoptive, step or foster parent is identified
  • an ‘Unrelated child (under 15 years)’ if no relative is identified in the same dwelling 

Persons aged 15 years and over are classified as: 

  • a child if they live with a natural, adoptive, step or foster parent
  • 'Not applicable' if they live with another family member such as a grandparent or sibling that is also aged 15 years and over, or if they are a boarder or lodger.

History and changes

A question on the relationships between members of a household has been asked in all Censuses since 1911. This variable has been output since 1991. 

In 2026, the variable name and category labels were updated to align with updated wording of questions on the form.   

Back to top of the page