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
30 December 2025
2.2. Metadata last posted
30 December 2025
2.3. Metadata last update
30 December 2025
3.1. Data description
Data and metadata are transmitted to Eurostat by the Member States in the framework of the Unified Demographic Data Collection which is in accordance with Regulation (EC) No 862/2007 and Regulation (EU) No 1260/2013 and their implementing regulations.
The regional breakdown of the Member States in the regional demographic tables is done under the most recent NUTS classification. There are agreements between Eurostat and Candidate countries as well as between Eurostat and EFTA countries, for which statistical regions have been coded in a way that resembles NUTS.
For more information on the versions in force, please see: Eurostat NUTS.
3.3. Coverage - sector
Not applicable.
3.4. Statistical concepts and definitions
See the table 3.4.1 in the annex POPSTAT_UNIESMS_A.
See the table 3.4.2 in the annex POPSTAT_UNIESMS_A.
3.5. Statistical unit
Number of persons.
3.6. Statistical population
See the table 3.6 in the annex POPSTAT_UNIESMS_A.
3.7. Reference area
Population, live births and deaths data are available at national and regional level.
3.8. Coverage - Time
Data on Resident Population and on Vital Statistics are available since 1900 (See table 15.2 in the annex for details).
3.9. Base period
Not applicable.
Data is collected at unit (person) level.
The reference date for population data is the end of the reference period (midnight of 31 December).
The reference period for vital events data is the calendar year in which the events occurred. The reference period for migration flow data is the calendar year in which the migration occurred.
6.1. Institutional Mandate - legal acts and other agreements
Not available.
6.2. Institutional Mandate - data sharing
Not available.
7.1. Confidentiality - policy
The data collected are covered by Article 6 (on statistic confidentiality), Law No. 22/2008, (Official Journal (OJ) No 92 1st Series, of 13 May 2008).
Population estimates are published at mid-June after the end of the reference year. Preliminary weekly data on deaths are made available 12 days after the end of the reference week. Monthly statistics on births, deaths and marriages are available 45 days after the end of the reference month. Annual data on births, deaths and marriages are published in April of the year following the data reference year and divorces on the 3rd quarter of the year following the data reference year. First results on immigration and emigration of the preceding year are available at mid-June and complete results at the end-September; annual Population estimates by citizenship and country of birth are published in November; annual statistics on foreign population and acquisitions of citizenship are published end-September. Annual yearbook “Demographic statistics” reference date of the preceding year is available online at mid-November.
8.2. Release calendar access
Please, consult the annex for the information on statistical information availability.
Microdata on Divorces, Marriages, Live Births and Deaths are made available to accredited researchers (researchers conducting R&D at Portuguese research institutions).
See the table 10.6 in the annex POPSTAT_UNIESMS_A.
10.7. Quality management - documentation
Not available.
11.1. Quality assurance
See the table 11.1 in the annex POPSTAT_UNIESMS_A.
11.2. Quality management - assessment
See the table 11.2.1 in the annex POPSTAT_UNIESMS_A.
See the table 11.2.2 in the annex POPSTAT_UNIESMS_A.
12.1. Relevance - User Needs
Not available.
12.2. Relevance - User Satisfaction
Not available.
12.3. Completeness
Not available.
13.1. Accuracy - overall
See the table 13.1 in the annex POPSTAT_UNIESMS_A.
See the table 13.1.1 in the annex POPSTAT_UNIESMS_A.
13.2. Sampling error
See the table 13.2 in the annex POPSTAT_UNIESMS_A
13.3. Non-sampling error
See the table 13.3 in the annex POPSTAT_UNIESMS_A.
14.1. Timeliness
According to Article 4(2) of the Commission Implementing Regulation (EU) No 205/2014, each year Member States shall provide the Commission (Eurostat) with data at national and regional level as described in Annex II and related standard reference metadata (in the metadata structure definition defined for the Euro SDMX Metadata Structure) for the reference year within 12 months of the end of the reference year. According to Article 3(2) of the Commission Regulation (EC) No 862/2007, Statistics on international migration, usually resident population and acquisition of citizenship shall be supplied to the Commission (Eurostat) within 12 months of the end of the reference year.
14.2. Punctuality
Not applicable.
15.1. Comparability - geographical
Data are fully comparable between geographical areas.
15.2. Comparability - over time
See the table 15.2 in the annex POPSTAT_UNIESMS_A.
15.3. Coherence - cross domain
Usual resident population is used for all statistical population and other statistical domains outputs.
Differences between Residence Permits Statistics and International Migration Statistics are due to the fact that Resident Permit Statistics are obtained via administrative records, namely from the Agency for Integration, Migration and Asylum, I. P. (AIMA), whereas International Migration Statistics are obtained from information from other statistical operations of Statistics Portugal – Migration Survey and Labour Force Survey – which are sources for estimating annual migration flows.
15.4. Coherence - internal
The internal coherence of the demographic balancing equation is assured.
Not available.
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. Minor revisions can occur annually on vital events data. Beside minor revisions that can occur, the post-census annual resident population estimates are provisional and are reviewed for the inter censuses years after the final data of the most recent population census. Annual estimates of emigrants and immigrants are reviewed every ten years along with the revision of the resident population estimates.
The resident population for 2011-2020 (based on the 2011 Census) were revised, 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. That is, on March 31st, 2023, the revised intercensal resident population for the period 2011-2020 (based on the results of the 2021 Census) were published. At the same date, the postcensal resident population for 2021 were released, substituting the ad-hoc exercise based on provisional results from 2021 Census.
18.1. Source data
See the table 18.1 in the annex POPSTAT_UNIESMS_A.
18.2. Frequency of data collection
Resident Population estimates are produced on an annual basis.
Data on births, deaths and marriages are provided on a daily basis to NSI.
Data on divorces, acquisitions of citizenship and legally induced abortions are provided on an annual basis to NSI.
Data on migration is annually collected.
18.3. Data collection
Statistics Portugal carry out the annual demographic data collection, based on:
Data on vital events collected by the Civil Registration Offices/Ministry of Justice, according to the data model designed by Statistics Portugal;
Data on acquisitions and loss of citizenship collected by the Civil Central Register/Ministry of Justice;
LFS and Emigration Survey estimates, surveys that are carried out by Statistics Portugal.
18.4. Data validation
Collected data are subject to a validation process that generally involves:
checks on file structure;
checks on the content of the file regarding:
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, regional and time series checks are performed to detect possible errors that could not be previously identified as long as the data is internally coherent. If any errors or incoherence is detected, the data provider is contacted for clarifications and/or corrections.
18.5. Data compilation
Statistics Portugal carry out the annual demographic data compilation, ensuring the coding of the variables to enter into the database in the case of vital events and estimating emigration and immigration flows, as well as the resident population figures obtained by applying the cohort component method.
18.6. Adjustment
Population of previous year plus natural change (live births minus deaths) plus net migration (immigrants minus emigrants) equals the population on 31 December of the reference year (the demographic balance for total population). This equation is not applied on population estimates by citizenship. Nevertheless, population data are consistent.
Data and metadata are transmitted to Eurostat by the Member States in the framework of the Unified Demographic Data Collection which is in accordance with Regulation (EC) No 862/2007 and Regulation (EU) No 1260/2013 and their implementing regulations.
See the table 3.4.1 in the annex POPSTAT_UNIESMS_A.
See the table 3.4.2 in the annex POPSTAT_UNIESMS_A.
Number of persons.
See the table 3.6 in the annex POPSTAT_UNIESMS_A.
Population, live births and deaths data are available at national and regional level.
The reference date for population data is the end of the reference period (midnight of 31 December).
The reference period for vital events data is the calendar year in which the events occurred. The reference period for migration flow data is the calendar year in which the migration occurred.
See the table 13.1 in the annex POPSTAT_UNIESMS_A.
See the table 13.1.1 in the annex POPSTAT_UNIESMS_A.
Data is collected at unit (person) level.
Statistics Portugal carry out the annual demographic data compilation, ensuring the coding of the variables to enter into the database in the case of vital events and estimating emigration and immigration flows, as well as the resident population figures obtained by applying the cohort component method.
See the table 18.1 in the annex POPSTAT_UNIESMS_A.
Births, deaths and marriages: monthly dissemination.
Population estimates, migration flows, acquisition of citizenship, divorces: annual dissemination.
According to Article 4(2) of the Commission Implementing Regulation (EU) No 205/2014, each year Member States shall provide the Commission (Eurostat) with data at national and regional level as described in Annex II and related standard reference metadata (in the metadata structure definition defined for the Euro SDMX Metadata Structure) for the reference year within 12 months of the end of the reference year. According to Article 3(2) of the Commission Regulation (EC) No 862/2007, Statistics on international migration, usually resident population and acquisition of citizenship shall be supplied to the Commission (Eurostat) within 12 months of the end of the reference year.
Data are fully comparable between geographical areas.
See the table 15.2 in the annex POPSTAT_UNIESMS_A.
