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.
[PT180] Agency for Integration, Migration and Asylum (AIMA)(Portugal)
1.2. Contact organisation unit
DPEE - Planning, Studies and Statistics Department
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
Agency for Integration, Migration and Asylum, I.P. (AIMA),
Avenida António Augusto Aguiar, 20,
1069 - 119 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
31 March 2026
2.2. Metadata last posted
31 March 2026
2.3. Metadata last update
31 March 2026
3.1. Data description
Data collection on Dublin statistics contains statistical information based on the Article 4.4 of Regulation (EC) No 862/2007 on Community statistics on migration and international protection.
Incoming ‘Dublin’ requests by submitting country (PARTNER), type of request, legal provision, sex and type of applicant (RI);
Outgoing ‘Dublin’ requests by receiving country (PARTNER), type of request, legal provision, sex and type of applicant (RO);
Incoming ‘Dublin’ requests based on EURODAC by submitting country (PARTNER), type of request, legal provision, sex and type of applicant (REDACI);
Outgoing ‘Dublin’ requests based on EURODAC by receiving country (PARTNER), type of request, legal provision, sex and type of applicant (REDACO);
Pending ‘Dublin’ incoming requests by submitting country (PARTNER), type of request, sex and type of applicant (RPENI);
Pending ‘Dublin’ outgoing requests by receiving country (PARTNER), type of request, sex and type of applicant (RPENO);
Incoming ‘Dublin’ requests for information by submitting country (PARTNER), legal provision, sex and type of applicant (RINFI);
Outgoing ‘Dublin’ requests for information by receiving country (PARTNER), legal provision, sex and type of applicant (RINFO);
Incoming responses to ‘Dublin’ requests for information by submitting country (PARTNER), legal provision, duration of response, sex and type of applicant (RESI);
Outgoing responses to ‘Dublin’ requests for information by receiving country (PARTNER), legal provision, duration of response, sex and type of applicant (RESO);
Unilateral ‘Dublin’ decisions by partner country, type of decision, sex and type of applicant (DUNI);
Decisions on incoming ‘Dublin’ requests by submitting country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DI);
Decisions on outgoing ‘Dublin’ requests by receiving country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DO);
Decisions on incoming ‘Dublin’ requests based on EURODAC by submitting country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DEDACI);
Decisions on outgoing ‘Dublin’ requests based on EURODAC by receiving country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DEDACO);
Incoming ‘Dublin’ transfers by submitting country (PARTNER), legal provision, duration of transfer, sex and type of applicant (TI);
Outgoing ‘Dublin’ transfers by receiving country (PARTNER), legal provision, duration of transfer, sex and type of applicant (TO);
Pending incoming ‘Dublin’ transfers by submitting country (PARTNER), sex and type of applicant (TPENI);
Pending outgoing ‘Dublin’ transfers by receiving country (PARTNER), sex and type of applicant (TPENO).
3.2. Classification system
Same as Eurostat.
See table 3.2. in annex "Quality report tables Dublin 2025."
3.3. Coverage - sector
Migration and Asylum – Dublin statistics.
3.4. Statistical concepts and definitions
Same definitions as Eurostat.
See table 3.4. in annex "Quality report tables Dublin 2025."
3.5. Statistical unit
The text of Art.4 of the Regulation (EC) 862/2007 on Migration and international protection refers in general to statistics based on the number of persons and not on the number of applications.
However, the article describing the 'Dublin' statistics (Art.4.4) refers to statistics based on the number of requests.
Commission services recommend that Art.4.4 (more precisely 4.4.a, 4.4.c and 4.4.d) is interpreted as referring to the number of persons concerned by each request, decision and transfer.
3.6. Statistical population
See table 3.6. in annex "Quality report tables Dublin 2025"
3.7. Reference area
Portugal.
3.8. Coverage - Time
Time coverage according to Regulation (EC) No 862/2007.
See table 3.8. in annex "Quality report tables Dublin 2025".
3.9. Base period
Not applicable.
Number (number of requests, number of decisions, number of transfers, etc.).
Calendar year.
6.1. Institutional Mandate - legal acts and other agreements
The Agency for Integration, Migration and Asylum (AIMA, I.P.) is the national authority responsible for the collection, processing, validation and transmission of Portugal’s Dublin statistics to Eurostat. Its mission and responsibilities are established by Decree-Law No. 41/2023 of 2 June and by its Statutes approved through Ordinance No. 324-A/2023 of 27 October.
The production and transmission of Dublin statistics are carried out in accordance with Regulation (EC) No 862/2007 on Community statistics on migration and international protection, as well as the methodological guidelines issued by Eurostat and the European Union Agency for Asylum (EUAA).
Within this framework, AIMA is responsible for the collection, compilation, validation and reporting of data relating to the implementation of the Dublin Regulation, including requests, transfers and responsibility determinations between Member States.
6.2. Institutional Mandate - data sharing
These data are produced from administrative records managed by AIMA’s specialised units, in accordance with the national legislative framework and the requirements of Regulation(EC) No 862/2007 on Dublin statistics. The processing workflow includes data collection, validation, quality assurance, and compilation prior to transmission to Eurostat.
7.1. Confidentiality - policy
Regulation (EC) No 223/2009 on European statistics (recital 24 and Article 20(4)), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.
No dedicated news release is issued for this dataset. Statistical information is made available through regular data transmissions to Eurostat and institutional communication channels when relevant.
10.2. Dissemination format - Publications
AIMA produces institutional publications related to migration and asylum, which are included in the Annual Report on Migration and Asylum.
These publications may include or provide context for relevant statistical information regarding Dublin matters.
10.3. Dissemination format - online database
There is no national online database providing public access to Dublin statistics produced by AIMA.
Statistical data on Dublin are not published through a specific public statistics portal. These data are transmitted directly to Eurostat and the EUAA regarding statistics on Dublin.
Dublin-related statistics for Portugal are made available to the public through Eurostat’s online database, where data sets from all Member States are published in a harmonized and comparable format.
10.3.1. Data tables - consultations
No national online data tables are available for public consultation regarding dublin statistics produced by AIMA.
The statistical data are not disseminated through a national statistical database or interactive table system.
Consultations of Portugal’s dublin‑related statistical tables are carried out exclusively through Eurostat’s online database, where harmonised tables for all EU Member States.
10.4. Dissemination format - microdata access
No microdata access is provided for asylum‑related statistics produced by AIMA.
The underlying records contain personal and highly sensitive information.
Access to such data is strictly prohibited under national legislation and under the EU General Data Protection Regulation (GDPR).
For these reasons, microdata cannot be anonymised in a manner that ensures full compliance with confidentiality and data‑protection requirements, and therefore cannot bemade available for research or external use.
Statistical output is disseminated solely in aggregated form through Eurostat’s harmonised data collections.
10.5. Dissemination format - other
No other specific national dissemination formats are used for asylum‑related statistics produced by AIMA.
Statistical information is disseminated exclusively through administrative reporting to Eurostat, in compliance with Regulation (EC) No 862/2007, and is not published inadditional formats such as newsletters, public dashboards, downloadable data tools, orinteractive visualisation platforms.
10.5.1. Metadata - consultations
Metadata relating to Portugal’s dublin statistics are not disseminated through any national platform.
Consultations of metadata take place exclusively through Eurostat’s online database andmetadata repositories, where harmonised metadata for all Member States are published in acomparable and standardised structure.
Therefore, users wishing to consult the metadata referring to Portugal must do so directlyvia Eurostat, within the Migration and Asylum statistics domain.
10.6. Documentation on methodology
The methodological documentation relating to dublin statistics produced by AIMA is developed on the basis of internal administrative procedures applied to the collection,validation and compilation of data.
The methodology follows the requirements of Regulation (EC) No 862/2007, as well as the methodological guidelines established by Eurostat and the European Union Agency for Asylum (EUAA).
All relevant methodological information is transmitted to Eurostat through formal reporting mechanisms, ensuring consistency, comparability and transparency in the statistical production process.
10.6.1. Metadata completeness - rate
The submitted metadata comply with the completeness requirements established by Eurostat for the migration and asylum statistics domain.
Any updates are incorporated on an ongoing basis, ensuring that Eurostat always hasaccess to the most up‑to‑date version of the national metadata.
10.7. Quality management - documentation
The quality management of asylum data follows the principles established in the European Statistics Code of Practice and the methodological guidelines provided by Eurostat.
Quality control procedures include:
Internal validation of administrative records;
Verification of coherence and temporal consistency;
Monitoring of potential inconsistencies and implementation of corrective measures;
Application of internal quality standards ensured by the responsible units.
11.1. Quality assurance
The quality assurance of asylum statistics produced by AIMA is based on the principles established in the European Statistics Code of Practice, ensuring rigour, transparency andreliability throughout all stages of the statistical production process.The quality assurance system includes:
Internal procedures for verification and validation applied to administrative records;
Technical supervision by the units responsible for statistical production;
Compliance with the methodological guidelines established by Eurostat and theEuropean Union Agency for Asylum (EUAA).
11.2. Quality management - assessment
Quality assessment is carried out on a continuous basis, with the aim of monitoring the performance of statistical processes and identifying areas for improvement.The process includes:
Periodic review of data collection, validation and processing practices;
Analysis of any inconsistencies, errors or deviations identified during verification stages;
Implementation of corrective measures whenever necessary, reinforcing the reliability and consistency of the data;
Ongoing updates to methodology and procedures, ensuring alignment with European requirements and statistical best practices;
Quality assessment prior to reporting to Eurostat, ensuring that the data meet the required standards of accuracy, completeness and comparability.
This structured process enables continuous improvement of statistical quality andcontributes to the credibility of national statistics within the European context.
12.1. Relevance - User Needs
The Dublin statistics produced by AIMA respond to the needs of a wide range of national and European users. The main users include:
Eurostat, for the compilation of harmonised European statistics on migration and international protection;
The European Union Agency for Asylum (EUAA), which uses these data for operational and strategic analysis;
The European Commission, for monitoring and evaluating EU asylum policies;
National governmental authorities, responsible for defining, monitoring and evaluating migration, integration and international protection policies;
International organisations and academic institutions, which use the data forresearch, planning and comparative analysis.
12.2. Relevance - User Satisfaction
There are currently no formal or regular mechanisms for directly measuring user satisfaction with Dublin statistics. Whenever additional information needs are identified, AIMA cooperates with European entities to adjust methodologies and ensure that national data remain relevant and fit forpurpose.
12.3. Completeness
The Dublin statistics produced by AIMA comply with the variables, concepts and breakdowns defined in Regulation (EC) No 862/2007, as well as with the methodological guidelines established by Eurostat and the EUAA.
All mandatory information, whenever possible, is collected, validated and reported within theregulatory deadlines.
See table 12.3. in annex "Quality report tables Dublin 2025".
12.3.1. Data completeness - rate
Not applicable.
13.1. Accuracy - overall
The accuracy of the asylum statistics produced by AIMA is considered adequate, as the data originate from mandatory administrative records collected within the framework of formal international protection procedures.
The information systems used ensure:
Systematic and complete recording of procedural events;
Minimisation of entry errors and duplication;
Traceability of changes or updates made
Explanation regarding some incomplete data:
DI / DO files
At present, it is not possible to extract information broken down by legal provision (article), as there are no specific codes available in the source systems to enable their identification and quantification. In this context, a request will be submitted to the DSI for the development and implementation of new codes, which should enable the proper collection, processing and reporting of this information in future.
RESI files
At present, it is not possible to extract information disaggregated by Duration, as there are no corresponding codes in the source system to enable its quantification. A request will therefore be submitted to the DSI for the development and implementation of the necessary codes, enabling the future collection and processing of this variable.
TI / TO files
At present, it is not possible to extract information disaggregated by legal provision (article) or by duration, as there are no specific codes available in the source systems to enable their quantification. A request will be submitted to the DSI for the development and implementation of new codes, which should enable the proper collection and reporting of this information in the future.
13.2. Sampling error
Sampling error does not apply to the Dublin statistics produced by AIMA.
13.2.1. Sampling error - indicators
Since no sampling methods are used, no sampling error indicators (such as coefficients ofvariation or margins of error) are calculated.
13.3. Non-sampling error
The data are based exclusively on administrative records collected throughout the entire Dublin procedure.
13.3.1. Coverage error
All information used by AIMA derives exclusively from mandatory administrative records collected within the framework of formal Dublin procedures.
Internal validation mechanisms further help minimise potential discrepancies related to duplication, missing records or misclassification.
Coverage errors occur at the moment of extracting the table from the database. In this moment, not all data regarding the reference period are recorded yet.
13.3.1.1. Over-coverage - rate
Not applicable.
13.3.1.2. Common units - proportion
Not applicable.
13.3.2. Measurement error
Not available.
13.3.3. Non response error
Not applicable.
13.3.3.1. Unit non-response - rate
Not applicable.
13.3.3.2. Item non-response - rate
Not applicable.
13.3.4. Processing error
Not applicable.
13.3.5. Model assumption error
Not applicable.
14.1. Timeliness
Data are collected continuously through administrative systems and consolidated manually, with efforts made, whenever possible, to submit within the deadlines established by Eurostat.
14.1.1. Time lag - first result
Data consolidation is carried out manually, which means that the dataset is made available shortly before the end of the reference period.
14.1.2. Time lag - final result
Final results are compiled and, whenever possible, submitted within the regulatory deadlines defined by Eurostat.
14.2. Punctuality
AIMA has made additional efforts to meet the delivery deadlines set by Eurostat for the transmission of statistical data in the Dublin domain.
See table 14.2. in annex "Quality report tables Dublin 2025".
14.2.1. Punctuality - delivery and publication
AIMA has been making significant efforts to ensure that data transmissions are sent to Eurostat punctually and in accordance with the official reporting calendar.
15.1. Comparability - geographical
The Dublin statistics produced by AIMA are fully comparable at the geographical level.
15.1.1. Asymmetry for mirror flow statistics - coefficient
Asymmetry in mirror flow statistics is not applicable to the Dublin statistics compiled by AIMA.
15.2. Comparability - over time
The temporal comparability of Dublin statistics is considered good, despite a significant institutional change: the transfer of responsibilities from SEF to AIMA on 29 October 2023.
Despite this transition, the statistical concepts, definitions and variables used have remained aligned with the European regulatory framework, ensuring methodological continuity.
The implementation of integrated information systems has made it possible to maintain consistent criteria for the registration, processing and classification of data, preserving comparability with previous time series.
See table 15.2. in annex "Quality report tables Dublin 2025".
15.2.1. Length of comparable time series
The time series remain comparable for the entire period during which Portugal has reported Dublin statistics to Eurostat under Regulation (EC) No 862/2007.
The institutional transition from SEF to AIMA did not compromise the continuity of the series, as:
Variables and classifications remained harmonised;
The administrative recording system was preserved and integrated;
No substantive changes were made to the statistical concepts.
Therefore, the available historical series (including periods prior to 2023) are considered fully comparable.
15.3. Coherence - cross domain
The harmonisation of the concepts used by AIMA with those defined by Eurostat and the EUAA ensures coherence between Dublin statistics;
15.3.1. Coherence - sub annual and annual statistics
Not applicable.
15.3.2. Coherence - National Accounts
Dublin statistics have no direct relationship with National Accounts.
Therefore, coherence checks with National Accounts are not required, and no relevant methodological intersections exist.
15.4. Coherence - internal
Internal coherence of Dubllin statistics is ensured through:
Centralised registration of all applicants and cases;
As a result, variables, categories and totals are consistent with each other, and all statistical outputs remain aligned throughout the entire process.
Not applicable.
17.1. Data revision - policy
Data revisions at AIMA are carried out regularly to ensure the quality of the work.
Throughout the year, occasional analyses are performed to verify whether the dataset is valid or requires updating.
Revisions follow the principles of transparency and traceability, ensuring that any change to previously reported data is documented and communicated to Eurostat clearly and with proper justification.
17.2. Data revision - practice
When data revisions occur, they are mainly due to:
Manual corrections to specific records (e.g., changes in case status or correction of classifications);
Late updates entered into the information system after the annual closing.
See table 17.2. in annex ‘"Quality report tables Dublin 2025".
17.2.1. Data revision - average size
Revisions tend to have an impact that generally results in:
Adjustments to the number of applications or decisions;
Late integrations that modify annual totals.
18.1. Source data
AIMA’s Dublin statistics are based exclusively on administrative records collected within the framework of formal procedures.
Data are entered into AIMA’s centralised information system, which is used by the operational units responsible for processing.
See table 18.1. in annex "Quality report tables Dublin 2025".
18.2. Frequency of data collection
For reporting to Eurostat, the data are consolidated on a Monthly, Quarterly and Annual.
18.3. Data collection
Data are entered directly by AIMA services responsible for processing Dublin cases.
18.4. Data validation
Data validation takes place at several stages:
Validation at the time of registration;
Manual verification by the responsible units whenever anomalies are detected;
Final verification to ensure compliance with Eurostat requirements.
18.5. Data compilation
Immigration and Borders Service Statistical System (SEFSTAT) - administrative data - linked with the National Immigration System (SIISEF), until October 28th, 2023.
Agency for Integration, Migration and Asylum, I.P. (SEFSTAT) - administrative data - linked with the National Immigration System (SIISEF), until March 31th 2024, and the new platform from AIMA since then.
18.5.1. Imputation - rate
Data compilation includes:
Extraction of relevant administrative records;
Cleaning and harmonisation of variables;
Monthly, quarterly or annual aggregation;
Construction of the reporting files.
18.6. Adjustment
Not applicable.
18.6.1. Seasonal adjustment
No statistical technique applied.
We're still updating our platforms due to the change in AIMA's structure, but with the support we've had from our partners I know that everything will always work out for the best, as always.
Data collection on Dublin statistics contains statistical information based on the Article 4.4 of Regulation (EC) No 862/2007 on Community statistics on migration and international protection.
Incoming ‘Dublin’ requests by submitting country (PARTNER), type of request, legal provision, sex and type of applicant (RI);
Outgoing ‘Dublin’ requests by receiving country (PARTNER), type of request, legal provision, sex and type of applicant (RO);
Incoming ‘Dublin’ requests based on EURODAC by submitting country (PARTNER), type of request, legal provision, sex and type of applicant (REDACI);
Outgoing ‘Dublin’ requests based on EURODAC by receiving country (PARTNER), type of request, legal provision, sex and type of applicant (REDACO);
Pending ‘Dublin’ incoming requests by submitting country (PARTNER), type of request, sex and type of applicant (RPENI);
Pending ‘Dublin’ outgoing requests by receiving country (PARTNER), type of request, sex and type of applicant (RPENO);
Incoming ‘Dublin’ requests for information by submitting country (PARTNER), legal provision, sex and type of applicant (RINFI);
Outgoing ‘Dublin’ requests for information by receiving country (PARTNER), legal provision, sex and type of applicant (RINFO);
Incoming responses to ‘Dublin’ requests for information by submitting country (PARTNER), legal provision, duration of response, sex and type of applicant (RESI);
Outgoing responses to ‘Dublin’ requests for information by receiving country (PARTNER), legal provision, duration of response, sex and type of applicant (RESO);
Unilateral ‘Dublin’ decisions by partner country, type of decision, sex and type of applicant (DUNI);
Decisions on incoming ‘Dublin’ requests by submitting country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DI);
Decisions on outgoing ‘Dublin’ requests by receiving country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DO);
Decisions on incoming ‘Dublin’ requests based on EURODAC by submitting country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DEDACI);
Decisions on outgoing ‘Dublin’ requests based on EURODAC by receiving country (PARTNER), type of decision, type of request, legal provision, sex and type of applicant (DEDACO);
Incoming ‘Dublin’ transfers by submitting country (PARTNER), legal provision, duration of transfer, sex and type of applicant (TI);
Outgoing ‘Dublin’ transfers by receiving country (PARTNER), legal provision, duration of transfer, sex and type of applicant (TO);
Pending incoming ‘Dublin’ transfers by submitting country (PARTNER), sex and type of applicant (TPENI);
Pending outgoing ‘Dublin’ transfers by receiving country (PARTNER), sex and type of applicant (TPENO).
31 March 2026
Same definitions as Eurostat.
See table 3.4. in annex "Quality report tables Dublin 2025."
The text of Art.4 of the Regulation (EC) 862/2007 on Migration and international protection refers in general to statistics based on the number of persons and not on the number of applications.
However, the article describing the 'Dublin' statistics (Art.4.4) refers to statistics based on the number of requests.
Commission services recommend that Art.4.4 (more precisely 4.4.a, 4.4.c and 4.4.d) is interpreted as referring to the number of persons concerned by each request, decision and transfer.
See table 3.6. in annex "Quality report tables Dublin 2025"
Portugal.
Calendar year.
The accuracy of the asylum statistics produced by AIMA is considered adequate, as the data originate from mandatory administrative records collected within the framework of formal international protection procedures.
The information systems used ensure:
Systematic and complete recording of procedural events;
Minimisation of entry errors and duplication;
Traceability of changes or updates made
Explanation regarding some incomplete data:
DI / DO files
At present, it is not possible to extract information broken down by legal provision (article), as there are no specific codes available in the source systems to enable their identification and quantification. In this context, a request will be submitted to the DSI for the development and implementation of new codes, which should enable the proper collection, processing and reporting of this information in future.
RESI files
At present, it is not possible to extract information disaggregated by Duration, as there are no corresponding codes in the source system to enable its quantification. A request will therefore be submitted to the DSI for the development and implementation of the necessary codes, enabling the future collection and processing of this variable.
TI / TO files
At present, it is not possible to extract information disaggregated by legal provision (article) or by duration, as there are no specific codes available in the source systems to enable their quantification. A request will be submitted to the DSI for the development and implementation of new codes, which should enable the proper collection and reporting of this information in the future.
Number (number of requests, number of decisions, number of transfers, etc.).
Immigration and Borders Service Statistical System (SEFSTAT) - administrative data - linked with the National Immigration System (SIISEF), until October 28th, 2023.
Agency for Integration, Migration and Asylum, I.P. (SEFSTAT) - administrative data - linked with the National Immigration System (SIISEF), until March 31th 2024, and the new platform from AIMA since then.
AIMA’s Dublin statistics are based exclusively on administrative records collected within the framework of formal procedures.
Data are entered into AIMA’s centralised information system, which is used by the operational units responsible for processing.
See table 18.1. in annex "Quality report tables Dublin 2025".
Dublin statistics are published once a year.
AIMA publishes annual data.
Data are collected continuously through administrative systems and consolidated manually, with efforts made, whenever possible, to submit within the deadlines established by Eurostat.
The Dublin statistics produced by AIMA are fully comparable at the geographical level.
The temporal comparability of Dublin statistics is considered good, despite a significant institutional change: the transfer of responsibilities from SEF to AIMA on 29 October 2023.
Despite this transition, the statistical concepts, definitions and variables used have remained aligned with the European regulatory framework, ensuring methodological continuity.
The implementation of integrated information systems has made it possible to maintain consistent criteria for the registration, processing and classification of data, preserving comparability with previous time series.
See table 15.2. in annex "Quality report tables Dublin 2025".
