Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
Department of Demographic and Social Statistics / Demographic Statistics Unit
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
Avenida António José de Almeida
1000-043 Lisboa
Portugal
1.6. Contact email address
Confidential because of GDPR
1.7. Contact phone number
Confidential because of GDPR
1.8. Contact fax number
Confidential because of GDPR
2.1. Metadata last certified
4 August 2025
2.2. Metadata last posted
4 August 2025
2.3. Metadata last update
4 August 2025
3.1. Data description
Total usually resident population for the purposes of qualified majority voting in the Council.
3.2. Classification system
Not applicable.
3.3. Coverage - sector
Total usually resident population at national level.
3.4. Statistical concepts and definitions
Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of at least 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
3.5. Statistical unit
Person.
3.6. Statistical population
Not applicable.
3.7. Reference area
Data are available at national level of geographical detail.
3.8. Coverage - Time
Comparable aggregated information is available since 1940.
3.9. Base period
Not applicable.
Person.
The reference date for population data is the end of the reference period (midnight of 31 December).
6.1. Institutional Mandate - legal acts and other agreements
Not applicable.
6.2. Institutional Mandate - data sharing
Not applicable.
7.1. Confidentiality - policy
Not applicable.
7.2. Confidentiality - data treatment
Not applicable.
8.1. Release calendar
Population estimates at the end of the year reference date of the preceding year are published at mid-June.
Concepts and methodology have been developed according to international standards.
11.2. Quality management - assessment
1. Nationals
Please indicate the type of duration of stay when counting a person with national citizenship as an usual resident with a minimum duration of stay of 12 months according to Art. 2(d) of Reg. 1260/2013.
1. Actual
2. Intended
3. Actual and intended
4. Other. Please specify below:
No
No
Yes
No
2. EEA Citizens
Please indicate the type of duration of stay when counting a person with EEA citizenship as an usual resident with a minimum duration of stay of 12 months according to Art. 2(d) of Reg. 1260/2013.
1. Actual
2. Intended
3. Actual and intended
4. Other. Please specify below:
No
No
Yes
No
3. NON-EEA Citizens
Please indicate the type of duration of stay when counting a person with non-EEA foreign citizenship as an usual resident with a minimum duration of stay of 12 months according to Art. 2(d) of Reg. 1260/2013.
1. Actual
2. Intended
3. Actual and intended
4. Other. Please specify below:
No
No
Yes
No
12.1. Relevance - User Needs
Data requested in Art. 4.1 of Reg. 1260/2013.
12.2. Relevance - User Satisfaction
Not applicable.
12.3. Completeness
Data transmitted as requested in Art. 4.1 of Reg. 1260/2013.
13.1. Accuracy - overall
The accuracy of population estimates is generally considered to be high. Population Census have been developed according to international standards. Data collection on births and deaths is exhaustive and based on administrative records (Civil Registration Offices/Ministry of Justice) and information provided by individuals. Migratory data are based on census, LFS and an LFS module of Emigration Survey data.
13.2. Sampling error
Not applicable.
13.3. Non-sampling error
Not applicable.
14.1. Timeliness
For the purposes of qualified majority voting in the Council, Member States shall provide the Commission (Eurostat) with data on the total population at national level at the reference time, in accordance with Article 2 ( c ), within eight months of the end of the reference year.
14.2. Punctuality
Not applicable.
15.1. Comparability - geographical
Not applicable.
15.2. Comparability - over time
Not applicable.
15.3. Coherence - cross domain
The total usually resident population transmitted by the national statistical offices to Eurostat in the framework of the Usually Resident Population data collection may differ from those available in National Accounts, Labour Force Survey or in the survey on Income and Living Conditions. The difference is given by the population coverage (see metadata specific to each domain).
15.4. Coherence - internal
The total usually resident population transmitted by the national statistical offices to Eurostat in the framework of the Usually Resident Population data collection may differ from those available in the rest of the Demographic domain. The difference is given by the population definition (see metadata specific to each domain).
Not applicable.
17.1. Data revision - policy
In general terms, revisions are mainly due to new data on the past that could not be incorporated in time of their previous release.
Taking into account the diversity of revision factors and the different frequencies of computation of statistical variables, as well as international experience in this field, revisions can be classified as follows: (1) regular revisions (current or general) and (2) extraordinary revisions.
The annual postcensal resident populations are provisional and are reviewed for the intercensal years after the final data of the most recent population census. The series of resident population 2011-2020 based on the 2011 Census was subject to revision, in order to make it compatible with the results of the 2021 Census, in accordance with Statistics Portugal Revisions Policy, in particular the regular general revisions that follow statistical operations of structural nature. The revised annual intercensal series of resident population 2011-2020 based on the results of the 2021 Census was released on March 31st, 2023. At the same date, data on resident population for 2021, the first year of the new post-Census 2021 series, was released. Data on resident population for 2024 refer to the fourth year of the new series of postcensal resident population based on the 2021 Census. Annual estimates of emigrants and immigrants are reviewed every ten years along with the revision of the resident population estimates.
Aditionally, resident population may also be revised due to new information that could not be integrated in time for their initial publication, as occured with the 2022 figures. 2022 Resident Population was revised, in June 2024, due to the inclusion in the resident population of displaced persons from Ukraine who are beneficiaries of the Temporary Protection regime in Portugal.
18.1. Source data
2021 Population Census, Vital Statistics (Civil Registration Offices/Ministry of Justice) and Household Surveys (LFS and an LFS module of Emigration Survey).
18.2. Frequency of data collection
Resident Population estimates are produced on an annual basis; data on births and deaths are provided on a daily basis to NSI; data on migration are collected annualy.
18.3. Data collection
The annual demography data collection at country level are carried out by Statistics Portugal.
Vital events on births and deaths are transmitted by Civil Registration Offices/Ministry of Justice to Statistics Portugal.
Emigrants and immigrants are estimated based on census and household surveys data.
18.4. Data validation
Data are subject to a validation process that involves:
a) checks on file structure;
b) checks of the content of file that covers:
Checking rules: fulfilling of the restriction(s) impose to the data.
Detecting missing values: when values were not provided.
Data validation: performed to check if specific logical conditions are fulfilled.
Finally time series checks are performed to detect possible errors that cannot be previously identified as long as the data is internally coherent.
If errors or incoherence of data is detected data provider is contacted for clarifications or corrections.
18.5. Data compilation
Based on the national microdata on demographic events transmitted, Statistics Portugal calculates aggregated data on births and deaths.
Emigrants and immigrants are estimated based on census and household surveys data.
Population estimates are obtained by applying the component method.
Total usually resident population for the purposes of qualified majority voting in the Council.
4 August 2025
Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of at least 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
Person.
Not applicable.
Data are available at national level of geographical detail.
The reference date for population data is the end of the reference period (midnight of 31 December).
The accuracy of population estimates is generally considered to be high. Population Census have been developed according to international standards. Data collection on births and deaths is exhaustive and based on administrative records (Civil Registration Offices/Ministry of Justice) and information provided by individuals. Migratory data are based on census, LFS and an LFS module of Emigration Survey data.
Person.
Based on the national microdata on demographic events transmitted, Statistics Portugal calculates aggregated data on births and deaths.
Emigrants and immigrants are estimated based on census and household surveys data.
Population estimates are obtained by applying the component method.
2021 Population Census, Vital Statistics (Civil Registration Offices/Ministry of Justice) and Household Surveys (LFS and an LFS module of Emigration Survey).
Annual
For the purposes of qualified majority voting in the Council, Member States shall provide the Commission (Eurostat) with data on the total population at national level at the reference time, in accordance with Article 2 ( c ), within eight months of the end of the reference year.
