Estimating Homelessness: Census methodology

People who identified themselves, or were identified by another household member, as being of Aboriginal origin, Torres Strait Islander origin, or both Aboriginal and Torres Strait Islander origin.

The address register was developed as the central source of addresses used in collection information to support 2021 Census, as well as all household and business collections. The main input to the Address Register is the Geocoded National Address File (G-NAF), supplemented by other available address data sources and field work by Australian Bureau of Statistics (ABS) Field Officers.

The Age (AGEP) variable collects each person's age. If age is not reported, it is imputed. See Imputation flag for age (IFAGEP). For infants aged less than one year, 0 years of age is recorded. Data is also available in 5 year groups (AGE5P) and 10 year groups (AGE10P)

Australia is defined in the Standard Australian Classification of Countries (SACC), 2016 and includes the states and territories and the other territories of Christmas Island, Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island. It excludes the other Australian external territories (Australian Antarctic Territory, Heard and McDonald Islands, Ashmore and Cartier Islands and the Coral Sea Territory). In 2011 and previous Censuses, Norfolk Island was not included in the definition of geographic Australia. Christmas and Cocos Keeling Islands have been included since the 1996 Census.

Australian born includes all people born in Australia and excludes people:

• Born overseas,
• Born at sea,
• Whose response was classified 'Inadequately described, or
• Whose response was classified 'Not elsewhere classified'.

Australia in this definition is as set out in section 2B of the Acts Interpretation Act 1901 and for the 2021 Census includes: the six states, the Northern Territory, the Australian Capital Territory, Jervis Bay Territory, and the territories of Christmas Island, Cocos (Keeling) Islands and Norfolk Island.

The Australian Defence Force service (ADFP) variable describes whether a person is currently serving or has previously served in the Australian Defence Force (ADF). The ADF includes:

• Australian Army (including NORFORCE (North-West Mobile Force)
• Royal Australian Navy
• Royal Australian Air Force

This variable also includes people who previously served in the National Service and the Second Australian Imperial Force. Regular service is considered a person’s main ongoing job, and most roles are full-time in nature.

Reserves service is normally part-time in nature and can include up to 200 days of service per year, depending on the role.

This variable does not capture people who have served in non-Australian defence forces.

The Australian Institute of Health and Welfare (AIHW) is a major national agency set up by the Australian Government under the Australian Institute of Health and Welfare Act to provide reliable, regular and relevant information and statistics on Australia's health and welfare. This agency manages and produces the Specialist Homelessness Services (SHS) Collection.

The Australian Statistical Geography Standard (ASGS) is a classification of Australia into a hierarchy of statistical areas. It is a social geography, developed to reflect the location of people and communities. It is used for the publication and analysis of official statistics and other data. The ASGS is updated every 5 years to account for growth and change in Australia’s population, economy and infrastructure.

The classification is conceptually based on Mesh Blocks and is split into two broad groups, ABS structures and the Non-ABS structures to satisfy different statistical purposes.

The ASGS ABS Structures used in this publication are:

• Statistical Area Level 2 (SA2)
• Statistical Area Level 3 (SA3)
• Statistical Area Level 4 (SA4)
• State/Territory (STE)
• Australia (AUS)
• Greater Capital City Statistical Areas (GCCSA) and
• Remoteness Area (RA).

The ASGS Non-ABS Structure used in this publication is:

• Local Government Area (LGA).

For more information refer to the ABS geography page and Australian Statistical Geography Standard (ASGS) Edition 3.

The Canadian National Occupancy Standard (CNOS) for housing appropriateness is sensitive to both household size and composition. CNOS assesses the bedroom requirements of a household by specifying that:

• there should be no more than two persons per bedroom;
• children less than 5 years of age of different sexes may reasonably share a bedroom;
• children 5 years of age or older of opposite sex should have separate bedrooms;
• children less than 18 years of age and of the same sex may reasonably share a bedroom;
• single household members 18 years or over should have a separate bedroom, as should parents or couples; and
• a lone person household may reasonably occupy a bed sitter.

Households living in dwellings where this standard cannot be met are considered to be overcrowded.

The homelessness estimation methodology uses the Housing suitability (HOSD) variable to identify usual residents in dwellings needing extra bedrooms under the CNOS. The variable is a measure of housing utilisation based on a comparison of the number of bedrooms in a dwelling with a series of household demographics.

Enumeration of people in caravans varies depending on their situation. Occupied caravans are usually treated as private dwellings with the exception of some caravans on residential allotments. Caravans that are occupied are usually treated as private dwellings. This includes caravans and campervans that are located on:

• caravan or residential parks
• camping grounds
• roadsides or open land.

Caravans on residential allotments are also usually treated as an occupied private dwelling. The exception to this is where there are one or more other structures on the allotment and the occupants of the caravan are residents of the main dwelling. In this case the occupants are all classed as one household and the caravan is counted as an additional room of the main dwelling.

The Australian Census of Population and Housing is an official count of population and dwellings, and collects details of age, sex, and other characteristics of that population. For more information see:

• Census methodology, 2021
• About the Census
• 2021 Census concepts.

The Census and Statistics Act 1905 (CSA) provides the Australian Statistician with the authority to conduct statistical collections, including the Census of Population and Housing, and, when necessary, to direct a person to provide statistical information. For more information see Legislative framework and Confidentiality.

The Census counts people where they were located on Census night and this count of the population is referred to as the place of enumeration count. A count of the population based on their place of usual residence is also available. In Censuses prior to 2006, many of the Census products presented data on a place of enumeration basis. Since 2006, the focus has been on place of usual residence.

Census counts by place of usual residence:

• exclude overseas visitors
• exclude Australian residents temporarily overseas.

This is a person of any age who is a natural, adopted, step, foster or nominal son or daughter of a couple or lone parent, usually resident in the same household. A child is also any individual under 15, usually resident in the household, who forms a parent-child relationship with another member of the household. This includes otherwise related children less than 15 years of age and unrelated children less than 15 years of age.

In order to be classified as a child, the person can have no identified partner or child of their own usually resident in the household. A separate family in the household is formed in this instance. If a person is aged under 15 and has a partner and/or a spouse these relationships are not recorded.

This is a person who has been classified as a child of another household member and who is aged under 15 years. A person who is classified as a child aged under 15 is considered to be a dependent child.

Under the Census and Statistics Act 1905 (CSA), the personal information you provide in the Census remains strictly confidential to the ABS. The ABS never has and never will release identifiable Census data. Other organisations, including government departments and marketing companies, cannot have access to personal information you provide on your Census form.  For more information refer to the 2021 Census Privacy Statement.

The Core Activity Need for Assistance (ASSNP) variable records the number of people with a profound or severe core activity limitation. People with a profound or severe core activity limitation are those needing assistance in their day to day lives in one or more of the three core activity areas of self-care, mobility and communication because of:

• a long-term health condition) lasting six months or more)
• a disability (lasting six months or more)
• old age.

The Country of birth of person (BPLP) variable indicates in which country a person was born.

A couple family is identified by the existence of a couple relationship. A couple relationship is defined as two people usually residing in the same household who share a social, economic and emotional bond usually associated with marriage and who consider their relationship to be a marriage or marriage-like union. This relationship is identified by the presence of a registered marriage or de facto marriage. A couple family can be with or without children and may or may not include other related individuals. A couple family with children present can be expanded to elaborate on the characteristics of those children, such as their number, age and dependency status.

Each stage of the Census is subject to stringent quality assurance procedures which result in data of high quality. However, in a Census there are recognised sources of error and some of these may survive in the data produced. Potential sources of error in the Census are: undercount, respondent error, processing error and introduced random error. Introduced random error is used to protect the confidentiality of individuals. The effect of such errors on overall Census results is generally insignificant and does not impair the usefulness of Census data.

Yet, as homelessness estimates are estimated from Census using analytical techniques, using both the characteristics observed in the Census and assumptions about the way people may have responded to particular Census questions, there are limitations of the Census data where underestimation or overestimation may occur for some homeless groups.

A dwelling is a structure which is intended to have people live in it, and which is habitable on Census night. Some examples of dwellings are houses, motels, flats, caravans, prisons, tents, humpies and houseboats.

Private dwellings are enumerated using online or paper household forms, which obtain family and relationship data as well as information on the dwelling itself such as rent or mortgage payments and ownership. Non-private dwellings (for example hotels and hospitals) are enumerated using online or paper personal forms. While these forms capture information about the person's residential status within the non-private dwelling, they do not capture information on ownership of, or payments related to, the dwelling.

All occupied dwellings are counted in the Census. Unoccupied private dwellings are also counted. This includes unoccupied units in retirement villages (self-contained). Unoccupied residences of owners, managers or caretakers of caravan parks, marinas and manufactured home estates are also counted, but other unoccupied dwellings in such establishments are not counted. Non-private dwellings with zero occupancy on Census night are not included in the homelessness estimates.

Since the 2001 Census unoccupied private dwellings have been counted in discrete Indigenous communities.

If a non-private dwelling is unoccupied on Census night it is out of scope. Unoccupied residences of owners, managers or caretakers of such establishments are counted.

See also Caravans, Dwelling location (DLOD), Dwelling structure (STRD), Dwelling type (DWTD), Household, Manufactured home estates , Type of non-private dwelling (NPDD).

Dwelling Location (DLOD) applies to private dwellings, and describes the location of dwellings other than 'typical' private dwellings. It classifies them into large communal locations, such as caravan parks and marinas. The majority of Private dwellings are in the ‘other’ category because they are not located within these types of communal locations.

Dwelling structure

The Dwelling structure (STRD) variable classifies the structure of private dwellings enumerated in the Census.

The broad categories are:

• Separate house: This is a house which is separated from other dwellings by a space of at least half a metre. A separate house may have a flat attached to it, such as a granny flat or converted garage (the flat is categorised under Flat or apartment - see below). The number of storeys of separate houses is not recorded. Also included in this category are occupied accommodation units in manufactured home estates which are identified as separate houses.
• Semi-detached, row or terrace house, townhouse, etc.: These dwellings have their own private grounds and no other dwelling above or below them. They are either attached in some structural way to one or more dwellings or are separated from neighbouring dwellings by less than half a metre.
• Flat or apartment: This category includes all dwellings in blocks of flats or apartments. These dwellings do not have their own private grounds and usually share a common entrance foyer or stairwell. This category also includes flats attached to houses such as granny flats, and houses converted into two or more flats.
• Caravan: This category includes all occupied caravans, regardless of where they are located. Occupied campervans are also included. For further detailed information see Caravans in this glossary.
• Cabins and Houseboats: This category includes all occupied cabins and houseboats. Cabins are self-contained and not intended for long term residential use. This includes occupied cabins located in residential parks or set up as temporary accommodation. A Houseboat is an occupied mobile dwelling (intended for use on water). It is not typically intended for long term use (although it could be currently used on a permanent or semi-permanent basis). Occupied houseboats are treated as occupied private dwellings regardless of location. It also includes occupied small boats.
• Improvised home, tent, sleepers-out: This category includes sheds, tents, humpies and other improvised dwellings, occupied on Census night. This category also includes people sleeping out, such as those sleeping on the streets, in abandoned buildings, under bridges or in cars.
• House or flat attached to a shop, office, etc.: A house or flat attached to a shop, office, factory or any other non-residential structure is included in this category.

See also Caravans, Dwelling, Dwelling location (DLOD), Dwelling type (DWTD), Tenure type (TEND), Type of non-private dwelling (NPDD).

The Dwelling type (DWTD) variable classifies dwellings into the following types:

• Private dwellings (occupied and unoccupied)
  • Occupied Private Dwelling: An occupied private dwelling is a private dwelling occupied by one or more people. A private dwelling is most often a house or flat. It can also be a caravan, houseboat, tent, or a house attached to an office, or rooms above a shop. Occupied dwellings in caravan/residential parks or camping grounds are treated as occupied private dwellings. Dwellings located in caravan/residential parks or camping grounds can be identified by using the variable Dwelling Location.
  • Unoccupied Private Dwellings: These are structures built specifically for living purposes which are habitable, but unoccupied on Census night. Vacant houses, holiday homes, huts and cabins (other than seasonal workers' quarters) are counted as unoccupied private dwellings. Also included are newly completed dwellings not yet occupied, dwellings which are vacant because they are due for demolition or repair, and dwellings to let. Unoccupied private dwellings in caravan/residential parks, marinas and manufactured home estates are not counted in the Census. The exception to this is residences of owners, managers or caretakers of the establishment and, from the 2006 Census, unoccupied residences in retirement villages (self- contained).
• Non-private dwellings
  • Non-Private Dwellings (NPD) are those dwellings, not included above, that provide a communal or transitory type of accommodation. They are classified according to their function for the variable Type of Non-Private Dwelling. NPDs include hotels, motels, guest houses, prisons, religious and charitable institutions, boarding schools, defence establishments, hospitals and other communal dwellings. People in NPDs are enumerated on personal forms and so information on their family structure is not available. In the case of accommodation for the retired or aged, where the one establishment contains both self-contained units and units that are not self-contained, then both household forms (self-contained) and personal forms (not self- contained) are used as appropriate. Unoccupied NPDs are not enumerated in the Census, with the exception of residences of owners, managers or caretakers within an NPD.
• Migratory, off-shore and shipping areas
  • Migratory: People enumerated on an overnight journey by plane, train or bus cannot be allocated a dwelling type. This category exists for processing purposes only.
  • Off-Shore: This includes dwellings such as off-shore oil rigs, drilling platforms and the like. Prior to the 2006 Census, it also included people enumerated aboard ships in Australian waters.
  • Shipping: This dwelling type is for people enumerated aboard ships in Australian waters. For the 2001 and earlier Censuses, they were included in the ‘Offshore’ category.

A dwelling is a structure which is intended to have people live in it, that is it was established for short-stay or long-stay accommodation.

See also Dwelling location (DLOD), Dwelling structure (STRD),Type of non-private dwelling (NPDD).

See Level of highest educational attainment (HEAP).

See Level of highest educational attainment (HEAP).

Persons in employment are those of working age who, during a short reference period, were engaged in any activity to produce goods or provide services for pay or profit. Employment is defined as an activity of one hour or more. 

See also Hours worked (HRSP), Labour force status (LFSP), Occupation (OCCP) and Part-time work.

Enumeration is the action of counting something. The Census enumerates (or counts) everyone in Australia on Census night, as well as all the dwellings.

See Place of enumeration, Place of usual residence (PURP).

The Estimated Resident Population (ERP) is the official measure of the population of Australia. It refers to all people, regardless of nationality, citizenship or legal status, who usually live in Australia, with the exception of foreign military or diplomatic personnel and their families. It includes usual residents who are overseas for less than 12 months over a 16-month period. It excludes overseas visitors who are in Australia for less than 12 months over a 16-month period.

A family is defined by the ABS as two or more persons, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually resident in the same household.

Each separately identified couple relationship, lone parent-child relationship or other blood relationship forms the basis of a family. Some households contain more than one family. Non-related persons living in the same household are not counted as family members (unless under 15 years of age).

Other related individuals (brothers, sisters, aunts, uncles) may be present in the household. If more than one family is present these people can only be associated with the primary family.

Visiting families are not included as part of the household, and the relationships of other visitors are not coded. A household containing only a visiting family (e.g. a family at a holiday home) is coded to a household type of visitors only.

Where all persons present are aged under 15 years, or where information for each person has been imputed, the household is deemed not classifiable to a family. Of people listed as temporarily absent, only spouse(s) and family children are used in coding family composition.

For further information on families and grandparent families, see Understanding Family composition and Grandparent families. 

To find out more information, see the fact sheet: Domestic and family violence.

The Census records the full/part-time status of students. See Type of educational institution attending (TYPP).

The Census provides a range of data over different areas and geography levels. The Australian Statistical Geography Standard (ASGS) defines all the geographies used by the ABS for release of data. Each geography has its own name, boundaries, and purpose. For more information and definitions on the geographies used in the 2021 Census, see Understanding Census Geography.

Greater Capital City Statistical Areas (GCCSAs) represent the functional area of each of the eight state and territory capital cities. See Australian Statistical Geography Standard (ASGS).

The ABS defines a group household as a household consisting of two or more unrelated people where all persons are aged 15 years and over. There are no reported couple relationships, parent-child relationships or other blood relationships in these households.

An unrelated child (e.g. boarder) under the age of 15 who lives in a household with one or more usual residents, is coded as forming a parent-child relationship within that household. These households become family households, not group households.

Group households are classified in the variable Household composition (HHCD), and individual members are classified in Relationship in household (RLHP).

The Highest year of school completed (HSCP) variable records the highest level of primary or secondary schooling completed. The data is used to help build a picture of the education levels attained in each area of Australia and to assist in the planning of educational facilities. Highest year of school completed is classified to the Australian Standard Classification of Education (ASCED).

Everyone in Australia at Census time needs to be counted in the Census, excluding foreign diplomats and their families, no matter where they may be sleeping on Census night. To achieve this, the ABS has developed a strategy to obtain the best possible enumeration of people, no matter where they sleep. Some aspects of this strategy include liaising with service providers and engaging specialised field staff to count people sleeping rough on a special interview based form, and providing the ability for people to respond to the usual residence question as 'none' if they have no usual residence.

For more information, see the Information Paper - A Statistical Definition of Homelessness.

ABS obtained lists of addresses of supported accommodation and boarding houses from government bodies, individual Specialist Homelessness Services (SHS) providers and umbrella homelessness services organisations.

In 2021, the ABS also sought information about what type of supported accommodation was provided i.e. whether it was crisis or transitional housing etc. Some of the lists ABS received included this extra detail, some did not.

Lists of boarding houses (both registered and illegal boarding house operations) were sought from jurisdictions and homelessness service providers in 2021 and were received from New South Wales, Victoria, Queensland, South Australia, and Northern Territory. Western Australia does not have a state-based register, yet information is available at the local council level. Tasmania has no requirement to maintain a register, while legal boarding houses do not operate in Australian Capital Territory.

The homeless operational groups (OPGP) variable records the operational group of persons estimated to be homeless or marginally housed on Census night.

See Marginally housing groups.

Advisory group to the ABS on the development, collection, compilation, production and dissemination of robust statistics for the use in analysing, understanding and reporting on homelessness in Australia. 

The Hours worked (HRSP) variable indicates the number of hours worked by the employed person in all jobs during the week prior to Census night, by employed people aged 15 years and over. This excludes any time off but includes overtime and extra time worked. Hours worked, when used in combination with Labour Force Status, provides information on full-time and part-time employment. For Census purposes, a person is considered to be working full-time if they worked 35 hours or more in all jobs during the week prior to Census night.

Occupied houseboats have been classified as occupied private dwellings since the 1986 Census, and therefore receive household forms. Unoccupied houseboats are not counted.

A household is defined as one or more persons, at least one of whom is at least 15 years of age, usually resident in the same private dwelling. Under this definition, all occupants of a dwelling form a household and complete one form. Therefore, for Census purposes, the total number of households is equal to the total number of occupied private dwellings as a Census form is completed for each household from which dwelling information for the household is obtained.

The Household composition (HHCD) variable describes the type of household within a dwelling. It indicates if a family is present on Census night and if other unrelated household members are present. A maximum of three families can be coded to a household. Lone person households can contain visitors. Visitor only households can contain overseas visitors.

The Census Household form (HHF) (online or paper) is the primary means for collecting Census data and is used in all private dwellings. The HHF records details about the dwelling and characteristics of people in the dwelling. It records details of up to six people on the paper form and up to 25 people on the online form. Extra forms are used if there are more people than this.

The Total household income (weekly) (HIND) variable is the sum of Total personal income (weekly) (INCP) of each resident aged 15 years or older who was present in the household on Census night.

If any resident aged 15 years and over is temporarily absent, or does not state their income, then a value for Total Household Income is not derived for that household. These households will be categorised as: 'Partial income stated' or 'All incomes not stated'.

• 'Partial income stated' is used when some household members (aged 15 years and over) are temporarily absent or have not stated their income.
• 'All incomes not stated' is used when no member of the household (aged 15 years and over) has stated their income.

In most cases, the income of visitors to a household is excluded. The exception to this is households that comprise only visitors. Household income is calculated for these households in order to collect data on household income in tourist areas.

These include sheds, tents, humpies and other improvised dwellings, occupied on Census night. This category also includes people sleeping rough, such as those sleeping on the streets, in abandoned buildings, under bridges or in cars.

See Dwelling; Dwelling structure (STRD).

Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived. In the Census, we impute key demographic variables (sex, age, marital status, and usual residence) where no Census form is returned or when a respondent does not respond to one of these questions.

Where a private dwelling is identified as occupied on Census night but a Census form has not been returned, people are imputed into that dwelling - both the number of people and their key demographic characteristics.

If a person in a non-private dwelling did not return a form, their demographic characteristics are imputed from people in similar non-private dwellings.

Where a person responds to the Census but does not answer the age, sex, marital status or usual residence questions, values are imputed using other information on the form as well as the distribution of these data items in the responding population. 

Imputation flag variables enable users of Census data to quantify the number of imputed records, for applicable data items, in a given population.

For more information on imputation see the Item non-response rates section in the Methodology. See also 2021 Census methodology, Derivation, Non-response, Hotdecking.

Income consists of all current receipts, whether monetary or in kind, that are received by the household or by individual members of the household, and which are available for, or intended to support, current consumption.

Income includes receipts from:

• wages and salaries and other receipts from employment (whether from an employer or own incorporated enterprise), including income provided as part of salary sacrificed and/or salary package arrangements
• profit/loss from own unincorporated business (including partnerships)
• net investment income (interest, rent, dividends, royalties)
• government pensions and allowances (includes pensions and allowances from Commonwealth and State and Territory governments as well as pensions from overseas)
• private transfers (e.g. superannuation, workers' compensation, income from annuities, child support, and financial support received from family members not living in the same household).

Gross income is the sum of the income from all these sources before income tax, the Medicare levy and the Medicare levy surcharge are deducted. Other measures of income are Disposable income and Equivalised disposable household income.

Note that child support and other transfers from other households are not deducted from the incomes of the households making the transfers.

The Indigenous status (INGP) variable records the response of persons who identified themselves as being of Australian Aboriginal and/or Torres Strait Islander origin in the Census.

Individual incomes are collected as ranges in the Census. To enable these range values to be summed, information from the Survey of Income and Housing, which collects income as individual values, is used to estimate the median income within each bracket collected by the Census. The relevant median value for each family/household member is then summed to produce family or household income. 

See also Income, Household income.

For Census purposes, the labour force includes people aged 15 years and over who:

• work for payment or profit, or as an unpaid helper in a family business, during the week prior to Census night;
• have a job from which they are on leave or otherwise temporarily absent;
• are on strike or stood down temporarily; or
• do not have a job but are actively looking for work and available to start work.

The following people are classified as being in the labour force:

• employed people (i.e. the first three groups above); and
• unemployed people (i.e. the last group above).

People aged 15 years and over who are neither employed nor unemployed are classified as not in the labour force. This includes people who are retired, pensioners and people engaged solely in home duties (unpaid).

See Labour force status (LFSP), Comparing the 2021 Census and the Labour Force Survey.

In the Census, the Labour force status (LFSP) variable is derived for all people aged 15 years and over. It records a person’s labour force status for the week prior to Census night. It classifies people as employed working full-time, part-time or away from work, unemployed looking for full-time work, looking for part-time work, or not in the labour force. The category 'Employed, away from work' also includes persons who stated they worked but who did not state the number of hours worked.

Labour Force Status is derived using responses to questions on:

• full/part-time job;
• job last week;
• hours worked;
• looking for work; and
• availability to start work.

The derivation methodology takes into account answers to these questions to derive the most appropriate Labour force status.

The Landlord type (LLDD) variable records the landlord type of rented dwellings. It applies to all occupied private dwellings that are being rented, including being occupied rent free. A private dwelling is defined in Dwelling structure (STRD) and can include caravans in caravan parks, occupied tents, and houseboats. Rented dwellings are classified in Tenure type (TEND).

The Level of highest educational attainment (HEAP) variable records a single measure of a person’s overall highest level of educational attainment, whether it be a school or non-school qualification. It helps to build a picture of educational attainment and qualifications across Australia and can be used to:

• compare with data collected in previous Censuses to help understand the changes of educational achievement in Australia over time
• determine the general level of educational achievement of the Australian population and of specific groups in Australian society
• investigate the relationship between levels of education and employment outcomes, income and other socioeconomic variables.

The ASGS Local Government Areas are an ABS Mesh Block approximation of gazetted local government boundaries as defined by each state and territory. ABS approximations of administrative boundaries do not match official legal boundaries and should only be used for statistical purposes.

There are 566 Local Government Areas covering the whole of Australia, including unincorporated areas, without gaps or overlaps. This incorporates 19 non-spatial special purpose codes including a new Outside Australia code.

A lone parent is a person who has no spouse or partner usually resident in the household, but who forms a parent-child relationship with at least one child usually resident in the household. The child may be either dependent or non-dependent.

Any private dwelling in which there is only one usual resident at least 15 years of age, is classified as being a lone person household.

Long-term health conditions are diagnosed by a doctor or nurse, last six months or longer and include health conditions that:

• may recur from time to time, or
• are controlled by medication, or
• are in remission.

See also Comparing ABS long-term health conditions data sources, Long-term health conditions, Type of long-term health condition (LTHP).

The ABS present, alongside the homeless estimates from the Census, estimates of the number of people in selected marginal housing circumstances. These marginal housing groups not only provide an indication of the numbers of people living in marginal housing close to the boundary of homelessness, but can also provide a possible indication of people who may be at risk of homelessness.

Three marginal housing groups are classified from the Census:

• People living in other crowded dwellings - those that are not in 'severely' crowded dwellings,
• People lin other improvised dwellings - that is those who were living in improvised dwellings but were not considered homeless under the rules for the group 'Persons living in improvised dwellings, tents or sleeping out'; and
• People who are marginally housed in caravan parks.

The Mortgage repayments (monthly) dollar values (MRED) variable records the monthly mortgage repayments being paid by a household for the dwelling in which they were counted on Census night. It is applicable to occupied private dwellings. A private dwelling is defined in Dwelling structure (STRD) and can include caravans in caravan parks, occupied tents, and houseboats.

The Census collects this information in single dollar values. For practical purposes this information is recoded to a specific number of ranges for standard Census products (such as QuickStats and Community Profiles). The ranges are listed in Mortgage repayments (monthly) ranges (MRERD).

Non-response refers to the situation where a response to one or more questions (items) on the form was not answered.

Item non-response occurs:

• where a household or person returns a form but does not answer one or more questions
• where a household or person does not respond to the Census at all.

For the key demographic variables (sex, age, marital status and usual residence) we impute values where non-response occurs. The corresponding imputation flags for these variables indicate if the item was imputed.

Where non-responding persons have been imputed, the remaining questions are either set to 'item non-response' or 'not applicable', depending on the imputed age of the person.

For detailed information on item non-response rates, see the Methodology. See also 2021 Census methodology. Derivation, Imputation.

The Non-school qualification: level of education (QALLP) variable describes the level of a person’s highest completed non-school qualification. Non-school qualifications are educational attainments other than those of a pre-primary, primary or secondary education level. This information about education will help to:

• build a picture of educational levels in each area of Australia
• show how different groups of people take part in education
• help to plan education services in different areas.

The full classification for levels of education, together with an explanation of the conceptual basis of the classification, can be found in the publication Australian Standard Classification of Education (ASCED).

Persons not in the labour force are those persons who, during the week prior to Census night, were neither employed nor unemployed. They include persons who were keeping house (unpaid), retired, voluntarily inactive, permanently unable to work, in gaol, trainee teachers, members of contemplative religious orders, and persons whose only activity during the week prior to Census night was jury service or unpaid voluntary work for a charitable organisation.

See also Labour force status (LFSP),

This dwelling variable provides a count of the number of bedrooms in each occupied private dwelling, including caravans in caravan parks.

The Occupation (OCCP) variable describes the primary job or occupation held by employed people in the week prior to Census night.

Occupation data in 2021 is available up to the 6-digit level. This allows for a more detailed look at occupation.

The variable Occupation experimental update version 1 (OCCEV1P) is also available, this is coded using the Australian and New Zealand Standard Classification of Occupations, 2021 Australian Update.

Homelessness is a phenomenon becoming more prevalent among the older population, aged 55 years and over. It generally relates to the inability to maintain or find housing due to a sudden change in an older person's circumstances; such as retirement, divorce, death of a partner/spouse, affordable housing and barriers to employment.

The term "or equivalent" can include:

• other terms used to describe years of schooling in Australia, which may have changed over time, as well as school level education undertaken at other institutions (e.g. TAFE)
• Year 12 equivalents can include: year 13, 6th form, Higher School Certificate and matriculation
• Year 10 equivalents can include: 4th form
• overseas qualifications comparable to Australian levels of schooling, for example the German Abitur is equivalent to year 12 in Australia

The International Baccalaureate is equivalent to year 12 in Australia.

Certificate level qualifications (e.g. Certificate I-IV) attained while studying at school are non-school qualifications and are not equivalent to school level qualifications (e.g. Year 12).

For information about how school and non-school qualifications are treated when determining highest educational attainment, see Level of highest educational attainment (HEAP).

Households living in dwellings requiring extra bedrooms according to the Canadian National Occupancy Standard (CNOS).  

See Canadian National Occupancy Standard (CNOS). 

For the 2021 Census, people are classified as overseas born if:

• they were born in a country other than Australia
• they were born at sea
• their response was classified 'Inadequately described'
• their response was classified 'Not elsewhere classified'.

Australia in this definition is as set out in section 2B of the Acts Interpretation Act 1901, and for the 2021 Census includes the states and territories and the other territories of Christmas Island, Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island. It excludes the other Australian external territories (Australian Antarctic Territory, Heard and McDonald Islands, Ashmore and Cartier Islands and the Coral Sea Territory).

See also Country of birth of person (BPLP) and Understanding Migrant statistics in the Census and other data sources.

See Visitors to Australia.

The existence of a parent-child relationship is one of the foundations on which separate families and particular family composition categories are identified. It only refers to relationships between people usually resident in the same household. It includes relationships in which people actually report a parent-child relationship on the Census form (including being an adopted child or a foster child of an adult), as well as some designated relationships (i.e. for children aged less than 15 years who do not otherwise have a parent in the household, in which case a nominal parent/child relationship is established).

An individual may be both a parent and a child of other people in the household. For example, a person could live with their father or mother and have a child of their own. If a child in a household is also identified as being a parent, then precedence is given to the person's role as a parent for family composition coding purposes.

See also Child, Family, Family composition (FMCF) and Parent.

A person identified as being in a couple relationship with another person usually resident in the same household is a partner. The couple relationship is established through reporting of either a registered or de facto marriage and includes same-sex couples.

A person is considered to be working part-time if they worked less than 35 hours in all jobs during the week prior to Census night. This is consistent with the definition of employed part-time in the Labour Force, Australia publication.

See also Labour force status (LFSP), Hours worked (HRSP).

The Census Personal form (online or paper) ecords details for one person only. It contains the same questions as the Census household form but excludes the questions related to the dwelling. It is used for people staying in a non-private dwelling such as a hotel, motel, hostel, or nursing home. It may also be used when a private dwelling requests an additional form (e.g. large households or if an individual wants to keep their responses private) and the household has already completed a household form.

The Personal Safety Survey (PSS) aims to collect information about men's and women's experience of physical or sexual assault or threat by male and female perpetrators. Experiences of the different types of violence, since the age of 15, by different types of male and female perpetrators (including current partner, previous partner, boyfriend/girlfriend or date, other known man or women, and stranger) is explored. More detailed information, such as where the incident occurred and what action was taken, can be obtained for most recent incidents of each of the different types of violence by a male and female perpetrator. Additional information is also collected about respondent experiences of current and previous partner violence such as frequency and fears of violence, incidents of stalking and other forms of harassment and general feelings of safety.

The ABS homeless operational group for people considered to be homeless who were in improvised dwellings, tents or sleeping out on Census night. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS homeless operational group for people considered to be homeless who were in supported accommodation for the homeless on Census night. This includes persons staying in dwellings classified as 'Hostels for the homeless, night shelter' as well as dwellings identified through the Homelessness list information. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS homelessness operational group for people considered to be homeless who were staying temporarily with other households on Census night. This group also includes some people who were homeless who are in 'visitor only' households. Some people who are homeless are likely to be underestimated in this category such as youth, those escaping family and domestic violence and Aboriginal and Torres Strait Islander peoples. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS homeless operational group for people considered to be homeless who were in boarding houses on Census night. Estimation techniques are designed to take account of legal and illegal boarding houses in the estimates. As a result this category is larger than the number of people enumerated in the non-private dwellings classified as "boarding house, private hotel". For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS homeless operational group for people considered to be homeless who had no usual address and were in other temporary lodgings: 'hotel, motel, bed and breakfast' on Census night. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS homeless operational group for people considered to be homeless who were living in severely crowded dwellings on Census night. This is operationalised in the Census as those people who were enumerated in a private dwelling that they were usual residents of and, according to the Housing suitability (HOSD) variable, the dwelling required four or more extra bedrooms to accommodate them. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

See also Canadian National Occupancy Standard (CNOS).

The ABS group showing people who were marginally housed in other crowded dwellings on Census night. This is operationalised in the Census as those people who were enumerated in a private dwelling that they were usual residents of and, according to the Housing suitability (HOSD) variable, the dwelling required three extra bedrooms to accommodate them. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

See also Canadian National Occupancy Standard (CNOS).

The ABS group showing people who were marginally housed. This includes people who were enumerated on Census night in the dwelling category of an 'improvised home, tent or sleepers out' who reported either being 'at home' on Census night or having no usual address, and are not considered, on balance, to be homeless. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness.

The ABS group showing people who were marginally housed and living in caravan parks where they reported a usual address in a caravan, cabin or houseboat in a caravan park and are unlikely to have accommodation alternatives. For more information about rules for estimating persons in this group, see Information Paper – A statistical Definition of Homelessness and Caravans.

Under the Census and Statistics Act 1905 (CSA) it is an offence to release any information collected under the Act that is likely to enable identification of any particular individual or organisation. To minimise the risk of identifying individuals in aggregate statistics, a technique has been developed to randomly adjust values. Random adjustment of the data, known as random error or perturbation, is considered to be the most satisfactory technique for avoiding the release of identifiable data while maximising the range of information that can be released. To learn more, see the 2021 Census methodology on Introduced random error/perturbation.  

See also Confidentiality.

The place of enumeration is the place at which the person is counted i.e. where they spent Census night, which may not be where the persons usually lives.

See also Comparing Place of enumeration with Place of usual residence and Place of usual residence (PURP).

The Place of usual residence (PURP) variable records the geographic area in which a person usually lives. It may or may not be the place where the person was counted on Census night. The base area for Place of usual residence (PURP) is a mesh block (MB). These can be aggregated to form higher Australian Statistical Geography Standard (ASGS) areas.

Census count of persons based on their reported place of usual residence.

The Census Post Enumeration Survey (PES) is a household survey conducted following the Census. The PES allows the ABS to estimate the number of people missed in the Census and the number counted more than once or in error. Historically more people are missed than are counted more than once in Australia, leading to a net undercount. PES estimates of net undercount are used to adjust Census counts for use in ERP.

The PES is only conducted in private dwellings therefore it cannot be used to estimate the undercount of homeless people on Census night. For more information see Post Census Review (PCR) and 2021 Census Overcount and Undercount.

A private dwelling (occupied or unoccupied) is a suite of rooms within a building that is self-contained and intended for long-term residential use. To be self-contained the suite of rooms must possess cooking and bathing facilities as building fixtures. For examples of private dwellings see Dwelling structure (STRD).

The Proficiency in spoken English (ENGLP) variable classifies a person's self-assessed proficiency in spoken English where they have identified they use a main language other than English at home (LANP). While people who use English only at home are included in this variable as a distinct category, they are not included in categories 2 to 5 which is the self-assessed ability in spoken English.

The Registered marital status (MSTP) variable records a person’s formal registered marital status. If registered marital status is not stated, it is imputed.

Remoteness Areas divide Australia and the states and territories into 5 classes of remoteness on the basis of their relative access to services. Remoteness Areas are based on the Accessibility and Remoteness Index of Australia (ARIA+), produced by the Hugo Centre for Population and Migration Studies.

See Australian Statistical Geography Standard (ASGS).

The Rent (weekly) dollar values (RNTD) variable records the individual dollar amounts of rent paid by households on a weekly basis for the dwelling in which they were counted on Census night. A private dwelling is defined in Dwelling structure (STRD) and can include caravans in caravan parks, occupied tents, and houseboats. 

In standard Census products (Quickstats, Community profiles), ranges are used rather than individual dollar amounts. The ranges are listed in Rent (weekly) ranges (RNTRD).

The Residential status in a non-private dwelling (RLNP) variable describes the residential status of each person in a non-private dwelling. It records whether people enumerated in non-private dwellings (such as motels, hospitals and colleges) are staying there as:

• members of staff of the accommodation (e.g. owner, proprietor, porter, cook, teacher, warden, family of owner or family of staff)
• residents
• guests
• patients
• inmates.

Housing and family relationship information is not available for people in non-private dwellings because they are counted using Personal forms.

Dwellings, people, and item response rates are internationally recognised measures that indicate the quality of Census data. Response rates give an overall indication of the number of responses to the Census, while item response rates are an indicator of a response to specific questions. For more information on response rates and item response, please see the Methodology, Census form and Understanding data quality. 

The dwelling response rate measures the number of private dwellings that returned a completed Census form, as a proportion of all private dwellings believed to be occupied on Census night. 

The person response rate measures how many people are included on a returned Census form as a proportion of all people (responding and non-responding) in Australia on Census night.

See also 2021 Census methodology.

Two persons of the same sex who report a de facto or married partnership in the relationship question, and who are usually resident in the same household, are a same-sex couple.

See also Marital status.

The 2021 Census of Population and Housing aimed to count every person in Australia on Census Night, 10 August 2021.

The people counted in the 2021 Census include:

• People in the six states and six territories (Northern Territory, Australian Capital Territory, Jervis Bay Territory, Territory of Christmas Island, Territory of the Cocos (Keeling) Islands and Norfolk Island)
• People who leave Australia but are not required to undertake migration formalities (e.g. people who work on oil or gas rigs)
• People on vessels in or between Australian ports
• People on board long-distance trains, buses or aircrafts within Australia
• People entering Australia before midnight on Census Night
• Visitors to Australia (regardless of how long they have been in the country or plan to stay)
• Detainees under the jurisdiction of the Department of Home Affairs in detention centres in Australia
• People in police lock-ups and prisons.

The people not counted in the 2021 Census include:

• People in Australian external territories (minor islands such as Heard and McDonald Island)
• Foreign diplomats and their families (derived from the Vienna Convention)
• Foreign crew members on ships who remain on the ship and do not undertake migration formalities
• People leaving an Australian port for an overseas destination before midnight on Census Night.

The 2021 Census of Population and Housing also counted private dwellings (such as houses, apartments and caravans) and non-private dwellings (such as hotels, hostels and hospitals).

The dwellings counted in the 2021 Census include:

• All occupied and unoccupied private dwellings
• Occupied caravans in caravan parks and manufactured homes in manufactured home estates
• Occupied non-private dwellings, such as hospitals, prisons, hotels, etc.
• Unoccupied residences in retirement villages (self-contained)
• Unoccupied residences of owners, managers or caretakers of such establishments.

Unoccupied non-private dwellings are out of scope of the 2021 Census.

The Sex (SEXP) variable records each person’s sex. A person's sex is based on their sex characteristics, such as their chromosomes, hormones and reproductive organs. If sex is not stated it is imputed.

The Specialist Homelessness Services (SHS) collection obtains information about people, adults and children, who seek assistance from specialist homelessness agencies. Services can include accommodation provision, assistance to sustain housing, domestic/family violence services, mental health services, family/relationship assistance, disability services, drug/alcohol counselling, legal/financial services, immigration/cultural services, other specialist services and general assistance and support.

This collection is compiled by the Australian Institute of Health and Welfare (AIHW). This collection only includes organisations that receive government funding to deliver specialist homelessness services and can be either not-for-profit or for-profit agencies.

See Australian Institute of Health and Welfare (AIHW).

The Special short form (SSF) is used in most areas of Australia to enumerate people who are sleeping rough. It is in paper format only and field staff use it to interview this population group. It records details for one person only and contains a small subset (10) of the same questions as the Census household form.

States/Territories are the largest spatial unit in the ASGS and are part of the Main Structure within ABS Structures. There are six states and six territories in the ASGS:

• New South Wales
• Victoria
• Queensland
• South Australia
• Western Australia
• Tasmania
• Northern Territory
• Australian Capital Territory
• Jervis Bay Territory
• Territory of Christmas Island
• Territory of the Cocos (Keeling) Islands and
• Territory of Norfolk Island

These spatial units are political entities with fixed boundaries. In aggregate, they cover Australia without gaps or overlaps.

See also Australian Statistical Geography Standard (ASGS) Edition 3.

The Statistical Area Level 1 (SA1) is the second smallest geographic area defined in the ASGS, the smallest being the Mesh Block. SA1s are built from whole Mesh Blocks. Whole SA1s aggregate directly to SA2s in the ASGS Main Structure.

The SA2s are a general-purpose medium-sized area built from whole SA1s. Their aim is to represent a community that interacts together socially and economically. Whole SA2s aggregate directly to SA3s in the Main Structure. SA2s do not cross State and Territory borders. In aggregate, they cover the whole of Australia without gaps or overlaps. 

The SA3s provide a standardised regional breakup of Australia. The aim of SA3s is to create a standard framework for the analysis of ABS data at the regional level through clustering groups of SA2s that have similar regional characteristics. SA3s are built from whole SA2s and aggregate directly to SA4s in the Main Structure.

The SA4 regions are the largest sub-State regions in the Main Structure of the ASGS. They are designed for the output of labour force data and reflect labour markets within each State and Territory within the population limits imposed by the Labour Force Survey sample. SA4s provide the best sub-state socio-economic breakdown in the ASGS and in rural areas generally represent aggregations of multiple small labour markets with socioeconomic connections or similar industry characteristics. SA4s are built from whole SA3s and aggregate directly to States and Territories in the Main Structure.

See Full/Part-Time student status.

The Supported Accommodation Assistance Program (SAAP) was established in 1985 to consolidate a number of Commonwealth, State and Territory government programs assisting people experiencing homelessness and those at risk of homelessness, including women escaping domestic violence. 

In 2011, the SAAP collection was replaced with the Specialist Homelessness Services (SHS) collection. 

The Census form seeks information about people who usually reside in a dwelling but who are temporarily absent on Census night. Coders use the following temporary absentees in determining household and family classifications:

• partners
• children
• co-tenants or unrelated flatmates (used to classify group households).

The only information gathered on temporarily absent persons are name, sex, age, Aboriginal and/or Torres Strait Islander origin, person's relationship in household and whether the person is a full-time student. This information is used to assist in family coding. All other information for persons temporarily absent and in Australia on Census night, should have been obtained at their place of enumeration. However, this information is not able to be related back to this dwelling.

See also Child, Household, Partner and Persons temporarily absent.

The Tenure type (TEND) variable describes whether a dwelling is owned, being purchased or rented.

The tenure category 'Being purchased under a shared equity scheme' refers to households who are purchasing less than 100% equity in the dwelling and may or may not be paying rent for the remainder.

‘Occupied under a life tenure scheme' refers to households or individuals who have a 'life tenure' contract to live in the dwelling but usually have little or no equity in the dwelling. This is a common arrangement in retirement villages.

People identified as being of Torres Strait Islander origin who are from the islands of the Torres Strait, between the tip of Cape York and Papua New Guinea. May also include people identified as being of both Torres Strait Islander and Aboriginal origin.

The Type of educational institution attending (TYPP) variable records the type of education institution being attended by people who are full-time or part-time students. The category covers preschool through to tertiary institutions. Information on whether a person is attending an education institution is essential for education and labour market planning.

The  Type of non-private dwelling (NPDD) variable records the type of non-private dwelling in which people were enumerated on Census night. Non-private dwellings are establishments which provide a communal type of accommodation. Examples of the information collected are: Hotel, motel; Boarding house, private hotel; Public hospital (not psychiatric); and Child care institution. See dwelling type (DWTD).

Although extensive efforts are made to contact all occupied dwellings and count all unoccupied private dwellings in the Census, locating and contacting them all is not possible. Some dwellings may not be identified. For example, flats above or behind shops or attached to private dwellings

may not be included in the Census. Analysis of the undercount in previous Censuses has shown that people away from their usual residence on Census night (for example, travelling, camping, staying in a non-private dwelling, or visiting friends) are more likely to be missed than people at home on Census night.

Even when a household is contacted, undercount is possible if not all members of the household can be included on the form (six people can be recorded on the paper form and 25 people on the online form) no extra online or paper forms are obtained. Undercount is also possible if the household, or a member of the household, refuses to cooperate and complete a Census form.

A measure of the extent of undercount is obtained from the Post Enumeration Survey (PES). The official population estimates produced by the ABS take into account the results of the PES. However, the Census counts are not adjusted.

See also the Methodology, 2021 Census overcount and undercount, Estimated Resident Population (ERP) and Post Census Review (PCR).

Unemployed persons are defined as all those of working age who:

• were not in employment
• carried out activities to seek employment during a specified recent period
• were currently available to take up employment given a job opportunity.

See also Labour force status (LFSP)

Usual address information is used to code usual residence.

See Usual residence.

Usual residence data provides information on the usually resident population of an area, and on the internal migration patterns at the state and regional levels. The 2021 Census has three questions on usual residence that ask where the person usually lives on Census night, and where the person usually lived one year ago and five years ago. Usual address information is used to code usual residence. Population measures based on place of usual residence are also referred to as the de jure population.

See also Comparing Place of enumeration with Place of Usual Residence, Place of usual residence (PURP), Usual address indicator Census night (UAICP), Temporarily absent, Visitors to a household.

For the purposes of homelessness estimation and estimating marginal housing, visitor only households are those dwellings where all persons in the dwelling reported no usual address and there were no usual residents.

See also Household composition (HHCD), Visitors to a household, Place of usual residence (PURP).

A visitor to a household is anyone who does not usually live in the household in which they were enumerated on Census night. Characteristics of individual visitors to a household are available at the household of enumeration.

The relationship of visitors to one another, or to any resident (including cases where all the people enumerated are visitors) is not further classified.

Households containing only visitors are excluded from family variables, and the internal migration variables.

See also Family, Household, Internal migration, Place of enumeration, Usual residence.

The question on the Census form, 'Where does the person usually live?' allows the identification of people who are usually resident in another country. These overseas visitors are identified as a separate category (coded as V) for all applicable variables.

For the 2006, 2011, 2016 and 2021 censuses, overseas visitors were those people who indicated they would be usually resident in Australia for less than a year.

See also Place of enumeration, Place of usual residence (PURP).

The Total personal income (weekly) (INCP) variable indicates the total income (in ranges) that a person aged 15 years and over usually receives each week. Equivalent annual income amounts appear in brackets.

Youth homelessness refers to those homeless youths aged between 12 and 24 years. This group is of interest as intervention (while in supported accommodation) with education and training programs leads to enduring housing outcomes. Some researchers define youth as aged 12–18 years. They may even dissect the age groups into 12–15,16–18 and 19–24 years due to the different characteristics of each, revolving around education and training, and labour force.

For information on the institutional environment of the ABS, including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, see ABS Institutional Environment.

This publication presents estimates of for the number and characteristics of experiencing homelessness in Australia at the time of the Census in 2021.  Prevalence estimates enable analysis of the scale of homelessness and can be used to report trends and to target services to prevent or improve the circumstances of homelessness through knowing both the locations of the homeless and their characteristics.

As homelessness itself is not directly measured in the Census, estimates are derived from Census data using a statistical definition of homelessness. The ABS definition of homelessness underpins the methodology used to compile the ABS estimates of homelessness. An overview of the definition is provided in the Methodology.

The Census and Statistics Act 1905 requires the Australian Statistician to conduct a Census on a regular basis. Since 1961, a Census has been held every 5 years. The 2021 Census was the 18th national Census and was held on the 10th August 2021. Data on homelessness have been collected in varying forms in the Census since 1933.

Homelessness estimates from the 2021 Census were released 22 March 2023.

The ABS aims to produce high quality data from the Census. To achieve this, extensive effort is put into Census form design, collection procedures and processing. There are four principal sources of error in Census data which quality management aims to reduce as much as possible. They are respondent error, processing error, non-response and undercount. For more detail see Managing Census quality.

The Census is self-enumerated and respondents sometimes do not return a Census form or fail to answer every applicable question. Persons are imputed into dwellings for which no form was returned, together with some demographic characteristics for these people (age, sex, marital status, usual address and place of work). These same demographic characteristics are imputed if not provided by respondents on a returned form. However, the majority of output classifications include a 'not stated' category to record the level of non-response for that data item. Data use considerations are produced for each Census variable and include non-response rates where relevant, along with a comparison of non-response rates for the 2016 Census and a brief outline of any known data quality issues. Data use considerations are included in the Census of Population and Housing: Census Dictionary, 2021.

The estimates use the ABS methodology for estimating homelessness from the Census, published in 2012 in Information Paper - Methodology for Estimating Homelessness from the Census of Population and Housing.

There are small changes and improvements in the methodology over time which may affect the ability to compare intercensal estimates. The methodology used in 2021 is described in the Methodology.

Detailed information on the estimation methodology and other technical aspects associated with the homelessness estimates are provided throughout this Methodology section. Additional information can be found in the Glossary included with this publication.

Tabulated data are freely available in Excel spreadsheets which can be accessed from the 'Data downloads' section.

Customised data are also available on request. Note that detailed data will be assessed for disclosure risk which in some cases may result in data being regarded as unfit for release.

A Census TableBuilder product: Microdata: Census of Population and Housing: Estimating homelessness will be freely available after release in April 2023. For further details, refer to the Microdata Entry Page on the ABS website.

For further information about these or related statistics, contact the Customer Assistance Service via the ABS website Contact Us page or complete a Consultancy Request Form.

The ABS Privacy Policy outlines how the ABS will handle any personal information that you provide to us.