25.4.2024 valid documentation

Basic data of the statistics

Data description

Families are formed at the turn of the year from persons living in the same dwelling according to the Population Information System maintained by the Digital and Population Data Services Agency and the State Department of Åland. The statistics contain families and families with children and their population data. Families are classified as married or cohabiting couples living without children or with children, registered male and female couples and single-parent families. “Without children” refers to couples without children but also to couples whose children have moved away from home. The statistics contain the age, language, nationality and country of birth of the spouses/parents, as well as the age and gender of each child living at home. A family with children is a family that includes at least one child under the age of 18.

Statistical population

The population permanently resident in Finland on the last day of the year.

Statistical unit

Family and person. Families are described with the help of the persons' background variables. All persons have their own person number, which is used in combining data with other individual-based data.

Unit of measure

The units of measure are the number of persons or families.

Reference period

The reference period of the statistics is a calendar year.

Reference area

Data are available on Finland on the level of the whole country and by various regional divisions based on the division of municipalities in Finland.

The classification into regions and the statistical grouping of municipalities have been used since 1997. The respective categories used prior to this were province and type of municipality. Since 1999, the regional division entering into force at the beginning of the year following the statistical reference year has been applied in the statistics on families.

Sector coverage

The statistics contain demographic data on all families and families with children permanently resident in Finland. The statistics contain the age, language, marital status, nationality and country of birth of the spouses/parents, as well as the age and gender and language (distributed into Finnish, Swedish, other language) of each child living at home. The data on spouses/parents also include the ordinal number of their marriage, as well as the latest marriage and divorce dates. In respect of registered partnerships, besides the dates of registration and annulment of registration, data on their possible marriages are also included. The data on a family also indicate whether it is a reconstituted family and how many underage children of each spouse and common children of the spouses the family includes.

In the statistics of the census year (every fifth year), data on the employment of parents/spouses, income data, data on housing, ownership of free-time residences and possession of cars are also combined with the families.

Individual data with identifiers must be kept undisclosed.

Time coverage

The first statistics on families are available from the population censuses of 1950 and 1960. Since 1970, population censuses have been conducted every five years. In addition, family data have been published in 1977, 1978, 1982, 1984 and 1987. Since 1992, family statistics have been compiled annually.

An annual review on cohabiting persons based on a sample of around 10,000 persons was carried out in connection with the Labour Force Survey from 1980 to 1989.

From 1870 to 1930, a population census based on individual forms was carried out every ten years in the largest towns. Some data on households are available from these censuses.

Frequency of dissemination

The statistics on families covering a calendar year are ready in May of the next calendar year unless otherwise stated.



Prior to 1997, changes in the statutory order of succession were classified as adopted children in the population statistics, although no actual adoptions were made. From the 1997 statistics, only actual adoptions have been recorded as adoptions.


Age refers to a person's age in whole years as at 31 December. The data are obtained from the Population Information System.

Age is also used as an auxiliary variable. For example, only people between 15 and 74 can be in the labour force.


In the family statistics children comprise the following persons living with their parents:
- biological children,
- adopted children,
- biological children, adopted children and confirmed children of one of the spouses.

Foster children and children in the care of the family are not classified as children.

The definition of child has changed since 1990. A child is now defined as a person who lives with his or her parents irrespective of his or her marital status, unless the person has a spouse or children who live in the same household-dwelling unit. In 1990 only unmarried persons were counted as children. So while in 1990 widowed or divorced persons living with their parents were classified as not belonging to families, since 1992 they have been regarded as members of the family.

Cohabiting couple

A cohabiting couple is defined as two spouseless adults of different sex aged 18 and over and occupying the same dwelling on a permanent basis, provided their age difference is less than 16 years and they are not siblings. In case the couple has a common child these specifications do not apply. Persons of the same sex living together are not regarded as cohabiting couples unless the household-dwelling unit consists of two women who are the biological mother of the child living in the same dwelling and the second mother confirmed for the child.

Family status

Family members are grouped by family status as follows:
- spouse, no children
- spouse with children
- cohabiting partner, no children
- cohabiting partner with children
- partner in a registered partnership, no children
- partner in a registered partnership with children
- father/mother without spouse
- child.

In the family statistics children comprise all persons, regardless of age, who live with their parents, or the spouse's biological, adopted or confirmed children, but not foster children or children in the care of the family.

Family with underage children

A family with underage children is a family comprising at least one child aged under 18 living at home.


Information on language is obtained from the Population Information System. At the same time as parents register the name of their new-born, they also indicate the child's mother tongue. That language is retained in the Population Information System unless it is changed upon separate application.

Languages are classified by the Population Register Centre according to the ISO 639 standard. The future language classification ISO-639-1 was already adopted for the 2000 population census.

Number of children

The number of children refers to the number of children who are living at home and have the status of a child. The number of children in families with underage children refers to the number of children aged under 18 living at home.

Reconstituted family

In a reconstituted family, a child aged under 18 is a child of only one of the spouses. Not all the children aged under 18 in the family are common children.

Type of family

Families are grouped into the following types:
- married opposite-sex couple without children
- married same-sex couple without children
- cohabiting opposite-sex couple without children
- married opposite-sex couple with children
- married same-sex couple with children
- cohabiting opposite-sex couple with children
- cohabiting same-sex couple with common children (biological mother and confirmed mother)
- registered male couple without children
- registered male couple with children
- registered female couple without children
- registered female couple with children
- mother with children
- father with children.

A married or cohabiting couple without children refers to a couple who has never had any children or whose children no longer live with their parents. ‘Cohabiting couple with children’ contains couples who have common children and also couples whose children are not common.

For reasons of data protection, married and cohabiting same-sex couples and registered same-sex couples are classified together with married opposite sex couples in municipal tables.

With a family

A man with a family is a married or cohabiting partner, a father with children and both partners of a registered male couple.

A woman with a family is a married or cohabiting partner, a mother with children and both partners of a registered female couple.

Accuracy, reliability and timeliness

Overall accuracy

The body compiling statistics on families in Finland is in a privileged position because the Population Information System is available, where each person has, in addition to a personal identity code, a place of residence code that indicates which dwelling the person lives in. The statistics on families can be compiled concerning the whole population annually, quickly and without burdening people with expensive inquiries. In addition to Finland, this is possible at least in Denmark.

Deduction of families from the Population Information System causes problems mainly in two respects:

1. Only persons who are registered at the same dwelling can be combined to a family.

2. Cohabiting couples (marriage-like relationship) must be deduced.

1. According to international concept definitions, a family can also be formed according to the official place of residence, as is done in Finland. However, families in which, for example, one of the spouses is registered in another locality because of work although they are staying with the rest of the family during weekends and holidays, are not complete in the statistics. Similarly, a couple can live together even though one of them is still registered somewhere else, for example with the previous spouse.

However, the majority of people in Finland live where they are registered. The Population Information System maintained by the Digital and Population Data Services Agency and the State Department of Åland can be regarded as very exhaustive in terms of persons. To obtain a personal identity code, a person has to be registered in the Population Information System. It is in practice impossible to live in Finland without a personal identity code. A personal identity code is needed so that one can work legally, open a bank account, have dealings with authorities, etc.

Since the discontinuation of yearly checking of domicile registers in 1989, the Population Information System has been maintained only by notifications of changes to population information. The Digital and Population Data Services Agency has requested Statistics Finland to carry out a sample survey on the correctness of address data. Around 11,000 persons are asked whether their address in the Population Information System is correct. In the latest survey 2012, the address was correct for 98.9 per cent of the respondents.

The Municipality of Residence Act has improved the deduction of young cohabiting couples. Now students can register in their place of study unlike before.

2. Deduction of a marriage-like relationship from the Population Information System is more problematic. The alternative is to exclude cohabiting couples without children completely from the statistics and combine cohabiting couples only with the help of common children. However, because statistics are meant to describe society as truthfully as possible, it is probably closer to the truth to deduct cohabiting couples based on a common address than to exclude them from the statistics.

The program most likely deduces non-existent cohabiting couples, on the other hand, it does not deduce cohabiting couples aged under 18 or cohabiting couples whose age difference is over 15 years. However, the number of cohabiting couples deduced by the program was very close to the figures obtained in interview surveys prior to initiating the deduction.

In 1989, cohabiting couples were still obtained with a separate interview survey. The targets of the interviews were persons, not families. The question was asked only of persons whose marital status was not “married”. Based on the sample, it was estimated that there were 372,000 cohabiting persons aged 15 to 64 in Finland. In the family statistics for the following year, 370,000 persons aged 18 to 64 were classified as cohabiting persons based on their address. However, some of them had the marital status “married”. According to the samples, the number of cohabiting couples grew by around 20,000 persons per year at the end of the 1980s.

Considering the differences in age limits and the importance of marital status in the inference of cohabiting couples, it can be concluded that the number of cohabiting couples deduced in family statistics is slightly lower than the real situation measured by samples. However, the inference of cohabiting couples gives a sufficiently good picture of the family structure in society. This allows us to monitor the trend of the development and to examine different family types as larger groups. However, caution is needed when making individual-level conclusions about these couples.


The data are released approximately five months after the reference period.


The data have been published almost without exception on the target date, so there has been no time lag. If the release of statistical data is significantly delayed from the announced point of time, information about the delay is posted on the home page of the statistics.


Comparability - geographical

Comparisons based on numbers of families can be made because the effect of regional mergers has been considered. It is common practice that the entire time series is updated with the temporally latest regional change.

Internationally, family data are best suited to be compared on the basis of population censuses, because in them the family is defined according to the same area conditions. At other times comparisons between different countries are difficult, if not impossible, because register-based family statistics compiled in the same way as in Finland do not exist in most countries.

Comparability - over time

Family data are not fully comparable before and after 1990, when cohabiting couples started to be deduced based on them living together. The family publication uses sample surveys to estimate the family distribution for the whole country for 1960 and 1970, inclusive of cohabiting couples without common children. The figures for 1980 and 1985 have been output with the new classification from the original data. Including cohabiting couples in the statistics increases the number of families and at the same time decreases the number of one-parent families, because some of the parents cohabit with a new spouse. In the family statistics, same-sex cohabiting couples are not deduced unless two women not married or in a registered partnership live together with a child to whom one of the women is the biological mother and the other the confirmed mother.

The fact that starting from 1990, no restrictions are imposed on the marital status of a person classified as a child also increases the number of families. Now, for example, a divorced person who returns to live with his/her mother forms a family with the mother, previously the mother and child were recorded as being outside the family population.

Coherence - cross domain

Statistics Finland’s other statistics use the data of population statistics as basic information on population. Thus, different statistics of Statistics Finland are consistent with each other as regards population data.

The figures of annually compiled family statistics differ from those of some population censuses. The concept used in these population census statistics is the household-dwelling unit population, in which case families whose dwelling does not fulfil the criteria for a dwelling are excluded from the statistics on families.

Coherence - internal

No differences.

Source data and data collections

Source data

Finnish population statistics are based on data obtained from the Population Information System maintained by the Digital and Population Data Services Agency and the State Department of Åland. Local population register authorities continuously update the Population Information System with information on population changes that occur among the population resident in the country. Since 1975, Statistics Finland has obtained population data weekly in machine-executable form from the Digital and Population Data Services Agency.

The last yearly checking of population domicile registers was carried out in Finland on 1 January 1989. Since then the Population Information System has been updated from change notifications. The data stored in the Population Information System are specified in the Act (21 August 2009/661) on the Population Information System and the certificate services of the Digital and Population Data Services Agency. Notifications on population changes for the ended year are awaited up to the last day of January of the following year.

The data for the statistics on population structure are drawn from the Population Information System. The data of the statistics on population structure are the basis for the family statistics.

Data collection

Since 1975, Statistics Finland has obtained population data weekly from the Population Information System maintained by the Digital and Population Data Services Agency and the State Department of Åland. The acquisition of data is based on Statistics Finland's position as a statistical authority as decreed in law.

Frequency of data collection

The data are collected annually.


Data compilation

Families are formed programmatically from the data on population structure when the persons have received a building and dwelling number.

Data validation

All persons must belong either to the family population or to persons without a family, and the sum of these two groups must be the same as the original population of the data. The distributions of the completed data are compared with the previous year, in addition to which there are numerous calculators and logical checks in connection with forming the data.

Principles and outlines

Contact organisation

Statistics Finland

Contact organisation unit

Social Statistics

Legal acts and other agreements

The compilation of statistics is guided by the Statistics Act. The Statistics Act contains provisions on collection of data, processing of data and the obligation to provide data. Besides the Statistics Act, the Data Protection Act and the Act on the Openness of Government Activities are applied to processing of data when producing statistics. 

Statistics Finland compiles statistics in line with the EU’s regulations applicable to statistics, which steer the statistical agencies of all EU Member States.  

Further information: Statistical legislation

Confidentiality - policy

The data protection of data collected for statistical purposes is guaranteed in accordance with the requirements of the Statistics Act (280/2004), the Act on the Openness of Government Activities (621/1999), the EU's General Data Protection Regulation (EU) 2016/679 and the Data Protection Act (1050/2018). The data materials are protected at all stages of processing with the necessary physical and technical solutions. Statistics Finland has compiled detailed directions and instructions for confidential processing of the data. Employees have access only to the data essential for their duties. The premises where unit-level data are processed are not accessible to outsiders. Members of the personnel have signed a pledge of secrecy upon entering the service. Violation of data protection is punishable. 

Further information: Data protection | Statistics Finland (stat.fi)

Confidentiality - data treatment

In population statistics, the identification data of an individual are pseudonymised, that is, the data of a person can no longer be linked to a specific person without additional information.

In accordance with data protection practices, rules concerning less detailed data are applied when distributing data by area if the table contains variables defined as sensitive. Then figures below the threshold value are not reported or they are not divided into categories of sensitive variables.

According to the Statistics Act, data released for research use must be edited into a form from which statistical units cannot be identified directly or indirectly. In order to prevent indirect identification, the key variables in terms of identification must be edited using statistical data protection methods suitable for the situation.

Releasing the sample instead of the total data is the main data protection method.
In addition to sampling, Statistics Finland has used, for example, less detailed classification of variables, removal of variables or suppression of the variable values received by an individual unit as data limiting methods.

Release policy

Statistics Finland publishes new statistical data at 8 am on weekdays in its web service. The release times of statistics are given in advance in the release calendar available in the web service. The data are public after they have been updated in the web service. 

Further information: Publication principles for statistics at Statistics Finland

Data sharing

Data on families are delivered to the Statistical Office of the European Union (Eurostat) and the United Nations Statistical Division as well as to the Nordic Statistical Yearbook.

Accessibility and clarity

Statistical data are published as database tables in the StatFin database. The database is the primary publishing site of data, and new data are updated first there. When releasing statistical data, existing database tables can be updated with new data or completely new database tables can be published.   

In addition to statistical data published in the StatFin database, a release on the key data is usually published in the web service. If the release contains data concerning several reference periods (e.g. monthly and annual data), a review bringing together these data is published in the web service. Database tables updated at the time of publication are listed both in the release and in the review. In some cases, statistical data can also be published as mere database releases in the StatFin database. No release or review is published in connection with these database releases. 

Releases and database tables are published in three languages, in Finnish, Swedish and English. The language versions of releases may have more limited content than in Finnish.   

Information about changes in the publication schedules of releases and database tables and about corrections are given as change releases in the web service.

Data revision - policy

Revisions – i.e. improvements in the accuracy of statistical data already published – are a normal feature of statistical production and result in improved quality of statistics. The principle is that statistical data are based on the best available data and information concerning the statistical phenomenon. On the other hand, the revisions are communicated as transparently as possible in advance. Advance communication ensures that the users can prepare for the data revisions. 

The reason why data in statistical releases become revised is often caused by the data becoming supplemented. Then the new, revised statistical figure is based on a wider information basis and describes the phenomenon more accurately than before. 

Revisions of statistical data may also be caused by the calculation method used, such as annual benchmarking or updating of weight structures. Changes of base years and used classifications may also cause revisions to data.

Quality assessment

The producers of Official Statistics of Finland have approved a common quality assurance in which they commit to common quality criteria and quality assurance measures. The quality criteria of Official Statistics of Finland are compatible with the European Statistics Code of Practice. The good practices followed in the statistics are presented in Statistics Finland's Quality Guidelines for Official Statistics handbook. Quality Criteria of Official Statistics of Finland.

The statistics on families were audited in 2014.

Quality assurance

Quality management requires comprehensive guidance of activities. The quality management framework of the field of statistics is the European Statistics Code of Practice (CoP). The quality criteria of Official Statistics of Finland are compatible with the European Statistics Code of Practice. 

User access

Data are released to all users at the same time. Statistical data may only be handled at Statistics Finland and information on them may be given before release only by persons involved in the production of the statistics concerned or who need the data of the statistics concerned in their own work before the data are published. 

Further information: Publication principles for statistics 

Unless otherwise separately stated in connection with the product, data or service concerned, Statistics Finland is the producer of the data and the owner of the copyright. The terms of use for statistical data.

Statistical experts

Marjut Pietiläinen
Senior Researcher
029 551 2798

The documentation released before 5.4.2022 can be found on the archive pages of the statistics.

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