Helping you help yourself

Our website has been designed to enable you to access the datasets you require in the most straightforward way possible.

However, we appreciate many of our users will have complex requirements, so below we have listed answers to the most frequently asked questions (FAQs) about the different types of data we hold. If you cannot find the answer you are looking for, please contact our Helpdesk using our online help form.

I’m looking for a specific type of data, how do I find it?

Browse ‘Different types of data’ in the ‘Help‘ section.
This is a good starting point for a wealth of established UK social surveys relating to areas such as population trends, the workplace, health and crime. Here, you will also find links to cross-national surveys, business data and the census.
We have also organised some of the key datasets into themes, such as ageing, economics, and mostly recently the impact of Covid-19, so you can search our collection by theme.

If you still can’t find what you are looking for, then you can enter key search terms in the search box of our data catalogue.


I’m researching my family history, can you help?

We are unfortunately unable to help you track down family members, as our service primarily supports social and economic research, but we do have some historical population data that may be useful, particularly on our Histpop site. We also provide links to other sites that are better sources for family history research.


What are international macrodata?

Macrodata are data aggregated to a country or regional level. The international macro datasets in the UK Data Service contain socio-economic time series data for a range of countries over a substantial time period. There are further details are available from international macrodata; you can also click on the filter ‘Data Type’ and choose ‘International macrodata’.


Census microdata

What are ‘census microdata’?

Census microdata are datasets consisting of random samples of anonymised individual records that have information collected about individuals and households from the UK censuses that are held every ten years. The main unit of observation is the individual. The responses of each individual to the different census questions are recorded separately in different variables.


What are the different levels of access to census microdata?

Census microdata are available as open data (without registration), safeguarded (downloaded after registration) and secure access (must be applied for and used in secure lab). See below for more details.


What are the different census microdata datasets available from the UK Data Service?

The UK Data Service has different levels of access to a wide range of census microdata from different years. These include:

Open access:

2011

  • The Census Microdata teaching datasets for England and Wales, Scotland and Northern Ireland (based on 1% sample of individuals).

1961-1981

  • The Census Microdata teaching datasets for Great Britain from the 1961, 1971 and 1981 censuses (based on 1% sample of individuals).

Safeguarded access:

2011

  • The Census Microdata Individual Safeguarded Sample (regional) from the 2011 censuses in England and Wales, Scotland and Northern Ireland (based on 5% sample of individuals).
  • The Census Microdata Individual Safeguarded Sample (local authority) from the 2011 censuses in England and Wales, Scotland and Northern Ireland (based on 5% sample of individuals).

2001

  • The Individual Licenced Sample of Anonymised Records (I-SAR) (regional) from the 2001 census for all countries of the UK (based on 3% sample of individuals).
  • The Small Area Microdata (SAM) (local authority) from the 2001 census for all countries of the UK (based on 5% sample of individuals).

There are also safeguarded microdata available for users who are interested in imputation that were created from the 2001 census microdata:

  • Individual Licenced Sample of Anonymised Records for Imputation Analysis (I-SAR) from the 2001 census for all countries of the UK (based on a 3% sample of individuals).
  • Small Area Microdata for Imputation Analysis (SAM) from the 2001 census for all countries of the UK (based on a 5% sample of individuals).

1991

  • The Individual Sample of Anonymised Records for Great Britain from the 1991 census (based on 2% sample of individuals).
  • The Household Sample of Anonymised Records for Great Britain from the 1991 census (based on 1% sample of households and households’ members).
  • The Individual Sample of Anonymised Records for Northern Ireland from the 1991 census (based on 2% sample of individuals).
  • The Household Sample of Anonymised Records for Northern Ireland from the 1991 census (based on 1% sample of households and households’ members).

1961-1981

  • The Census Microdata Individual Files for Great Britain from the 1961, 1971 and 1981 censuses (based on 5% sample of individuals).
  • The Census Microdata Household Files for Great Britain from the 1961, 1971 and 1981 censuses (based on 0.95% sample of households and households’ members).

The Integrated Census Microdata (I-CeM), 1851-1911

The UK Data Service provides safeguarded access to the Integrated Census Microdata (I-CeM). These are microdata from most of the censuses that were carried out in the UK between 1851 and 1911. Detailed information on how to obtain the I-CeM from the UK Data Service is provided below.

Secure access:

In addition to these key data, there are census microdata available through Secure Lab access:
2001

  • The Household Sample of Anonymised Records (HSAR) from the 2001 census (based on 1% Sample of households in England and Wales only). 1961-1981
  • The Census Microdata Individual for Great Britain from the 1961, 1971 and 1981 censuses (based on 9% sample of individuals).

Can I find information about a particular individual in the census microdata?

No, the data are at the individual level but you cannot identify a particular individual from the census microdata files as the amount of detail available is restricted to a non-disclosive level and individual respondents only appear in one file. These measures were taken in order to ensure that a strict confidentiality of the data is maintained.


What is the difference between ‘SARs’ and ‘census microdata’?

They are the same. Because of the structure of the dataset, census microdata were previously known as Samples of Anonymised Records (SARs). This term is still used in the names of the 1991 and 2001 files. In the 2011 census, the name was changed from SARs to Census Microdata.


What topics do census microdata cover?

The census collects a variety of topics at individual and household level. The teaching and safeguarded microdata files (1991-2011) cover different aspects including demographic characteristics, migration, education, employment, health indicators, household condition and amenities, language and social class. An Excel spreadsheet showing in detail the topics covered in each microdata file is available on the Census microdata pages.


Why are census microdata a useful resource for research or reports?

The census microdata have the following properties:

  • They contain a variety of sociodemographic characteristics of respondents, with a particular focus on individual, household, and geographical information.
  • They have large sample sizes at individual level which makes them particularly useful for exploring lower level geography, and smaller subpopulations such as ethnic minorities. For example, the 2011-Open data have a 1% sample of individuals. The sample size of the 2011-Safeguarded data are 5% sample of cases in each file (Regional and Local authority). The 2011-Secure data have larger sample sizes, the files are based on 10% samples.
  • They are nationally representative.
  • Individual records consist of a broad range of households and households’ members characteristics, which enable multivariate analyses for different purposes.
  • Microdata files are flexible as users can generate statistics, define tables and create new variables from the data in any desired manner.
  • Most microdata files can be downloaded from the website after registration.

Can I analyse census microdata without a statistical package?

Our online data exploration tool Nesstar allows users to access and carry out basic analyses online to a wide range of microdata, including some census microdata. The system allows users to browse metadata (information about the data) and variable distributions. It also enables users to perform simple online cross-tabulations, produce graphs and download subsets of variables in different formats. For more complex analyses, users are advised to use statistical software packages such as SPSS, Stata, SAS or R.


Is there a preferred statistical package for using the UK Data Service census microdata?

Census microdata are downloadable in different format such as SPSS, Stata, SAS, CSV, Delimited, Statistica, Nesstar Publisher, DIF, NSDstat, Textfile. Users may select the format suitable for importing the data into their preferable statistical package and can download the data into their machines.


Are census microdata available to the UK public?

Microdata files are available at three different access levels, two of which you can access via the UK Data Service. The three levels are:

Microdata available from the UK Data Service:

  • Open data: The open access teaching datasets are available for teaching only. They are not intended to be used for non-teaching purposes – users should use safeguarded or secure data for research or reports. The dataset available as SPSS/Stata format from UK Data Service without the need for registration. These data are also available in spreadsheet format (csv files) from the main census offices.
  • Safeguarded data: census data from 1961 to 2011, available from the UK Data Service. These datasets are available to registered users who have agreed to the online licence conditions. Some can be downloaded after registration with the UK Data Service, and others require an application process.

Data only available from census offices:

  • Secure (or controlled) data: The Household Sample of Anonymised Records (HSAR) from the 2001 census in England and Wales and the 1961-1981 censuses in Great Britain are available through the UK Data Service Secure Lab. There are other censuses microdata available through census offices only: Office for National Statistics (ONS) is responsible for the Census for England and Wales, and additionally for disseminating census statistics for the UK; National Records Scotland (NRS) is responsible for the Census for Scotland; and Northern Ireland Statistics and Registration Agency (NISRA) is responsible for the Census for Northern Ireland.

Where can I find more information about census microdata?

For more information about accessing census microdata through the UK Data Service, please visit the Get census microdata page.

For information about terms and conditions of data access and the UK Data Service data access policy, please visit Types of data access.


Can I reuse microdata that I already obtained from the UK Data Service for a new project?

No, users must download the data again creating a new project if data will be used for any new purpose or project. Where permission from the data owner is required, you will need to make a new application for the data.


As a researcher living outside the UK, can I access any census microdata available in the UK Data Service?

Open teaching dataset(s): Anyone can access the census microdata open access teaching datasets, which can be downloaded without registration. These files contain only a small number of variables and are intended to be used for teaching purposes only.

All other census microdata: For data held under other licences, under the European Union law, the UK Data Service is unable to release some census microdata data to users outside the European Economic Area (EEA). Therefore, census microdata files are only available to UK applicants and not available to overseas users without permission from the main census agencies: Office for National Statistics (ONS), National Records Scotland (NRS) and /or Northern Ireland Statistics and Registration Agency (NISRA). The UK Data Service is obliged to request permission from the censuses offices prior to releasing the data to non-UK residents. The owners of census microdata have specified that only data users within the EEA and the other countries deemed by the European Commission to be able to safeguard the data, can be allowed access to some census microdata held in UK Data Service. Applications from non-UK residents will only be accepted from applicants resident in the EEA or in countries considered by the European Commission to have an adequate level of protection for personal data (http://ec.europa.eu/justice/data-protection/international-transfers/adequacy/index_en.htm).


Why are some projects subject to charges?

Data from the UK Data Service platform, including census microdata, can be downloaded free of charge for non-commercial purposes. If a project is deemed to be commercial, charges will be applied. Data requested for commercial use are subject to an administrative charge. The UK Data Service would also need to seek permission from the data depositors to grant access for commercial projects. Find out more on our How can I use your data for my project? and How to register if you are not an UK academic user pages.


How can I obtain the historic microdata from the UK Data Service (1961-1981)?

The UK Data Service provides three levels of access to microdata from the censuses that were conducted in Great Britain in 1961, 1971 and 1981:

  • Open data: The 1961-1981 census microdata teaching datasets. These datasets are available free of charge for anyone to download under an Open Government Licence.
  • End User Licence: The 1961-1981 census microdata at this level are only available to registered users who have agreed to the licence conditions. UK users can download the data from the website after agreeing to the licence conditions.
    For overseas users, data at this level are available to researchers based within the European Economic Area with data owner’s permission. This requires the UK Data Service to seek approval from the main census office before making the data available to download. To request access to the historic data, applicants are requested to send a detailed project abstract to the UK Data service Helpdesk (help@ukdataservice.ac.uk), indicating the work that they intend to carry out using the requested dataset(s) and the aim of this work. If the applicants are students, they also need to send a reference from a senior academic at their institution. The referee should state that the applicant is trustworthy and capable of handling and analysing the data. The reference letter can be sent directly to our helpdesk by the referee, or they can provide it as a PDF document on university headed paper, then applicants can send to our helpdesk together with the abstract. The UK Data Service will internally process the request and then will pass it to the data owners for consideration. If they approve the request, UK Data Service would then make the data available for applicant to download.
  • Secure Access: The 1961-1981 census microdata at this level are only available for UK users through the Secure Lab arrangements Secure Lab.

For more information about historic census microdata, please visit the Enhancing and Enriching Historic Census Microdata (EEHCM) project page.


How can I obtain the Integrated Census Microdata (I-CeM), 1851-1911 from the UK Data Service?

The Integrated Census Microdata (I-CeM) are microdata from the censuses that were carried out in the UK between 1851 and 1911. However, the 1871 England and Wales Census data and the 1911 Scottish Census data are not included in I-CeM.

Some of these data are available online at Integrated Census Microdata and ICeM-Nesstar. The purpose-built I-CeM system of the I-CeM project allows users to filter the database of a wide range of census records based on specific key variables. It also allows users to download the resulting data table of individual census records with over 100 variables per record. The ICeM-Nesstar system enables users to explore and browse the I-CeM data online by carrying out simple online analysis such as tabulation, correlation and regression analyses and exporting statistical tables. In order to download these data, users are advised to contact the UK Data Service helpdesk.

For accessing the names and address of the I-CeM data collection, which enable linkage across census years, a special application must be made as per the data owners’ request. To obtain access, users must complete and return the Special Licence application form. The UK Data Service will have to seek explicit permission from the data owners to grant users access to I-CeM data. Find information on applying for Special Licence data in our Types of data access page. Guidance on how to complete the Special Licence application form is presented in the form. Users must be aware that they must use a computer at their workplace in order to access the I-CeM Special Licence data.

There are also additional datasets that have been derived from the I-CeM project. Some of these data are made available to users via ReShare repository without the requirement for registration for download/access. For some dataset, users need to request access permission by contacting skw30@cam.ac.uk. Users must specify the reason for wanting access to these data. Once permission is obtained, users should forward it to reshare@essex.ac.uk. Users will be informed when the data is ready for release.

For more information about the I-CeM, please visit the Integrated Census Microdata (I-CeM), 1851-1911 catalogue record page.


Can I access the census longitudinal data from the UK Data Service?

The census longitudinal data are not available at the UK Data Service, but they can be found at CeLSIUS (for England and Wales) and SLS-DSU (for Scotland). Information related to all three UK census-based longitudinal studies are available at CALLS Hub.


What other census data products can I get and where can I get them from?

In addition to census microdata, the UK Data Service also hold aggregate, flow and boundary census data, as well as other data related to census such as Experian, deprivation and population data.

For more information about the census data or data related to census in the UK Data Service, please visit the Census data section of Learning hub. You can also check the three main census offices: Office for National Statistics (ONS); National Records Scotland (NRS); and Northern Ireland Statistics and Registration Agency (NISRA).


Where can I find more information about UK censuses?

We provide general information about census data such as how to access census data, guides to data types, questionnaires, definitions, how to cite census data,…. etc. in the Census data section of Learning hub.


About Census flow data

What are the Census flow data?

The Census flow data are data about moves between two locations. These include migration flows and journeys to work. They are also referred to as ‘origin-destination data’ and ‘interaction data’.


What census data are available?

The UK Data Service provides access to flow data from the 1981, 1991, 2001 and 2011 Censuses, as well as additional non-Census data.


Are all the datasets from 2011 Census already available?

Yes, the entirety of 2011 Census open and safeguarded tables have been released via the queryable WICID tool and as static downloads. The first batch of 2011 Census data was released in late July 2014, and we continued to publish new tables until mid-2015. More data might be released in the future in cases such as if ONS decides to reclassify some secured tables to safeguarded. However, no such plans are currently in place.


When will 2021 Census data be released?

According to the dissemination plans by ONS, 2021 census flow data are expected to be released in 2023. However, because of National Records of Scotland’s decision to postpone census to 2022 due to the Covid-19 crisis, the first batches of 2021 census data are not expected to be UK wide. The arising issues and mitigation methods to harmonise data across all agencies are currently being discussed.


Getting access to the data

Who can access the Census data provided by the Flow Data Service – do I need a username/password?

Explicit registration is not required for 1981 to 2001 and public 2011 census data products. However, outputs from the 2011 Census tagged as ‘safeguarded’ require users to agree on additional terms and conditions. Access to these datasets is permitted via Federated Access. Prospective users of safeguarded data need to register with UK Data Service prior to using Federated Access.


What is Federated Access?

Federated Access is also known as:

  • Shibboleth
  • The UK Federation
  • The UK Access Management Federation
    It allows users to securely access external services using the same username and password as they do for local services at their institution. Most institutions use Federated Access.

Users can be granted access to the ‘safeguarded’ datasets if they are:

  • Students or staff in UK universities
  • UK government staff
  • NHS staff
  • Research Council staff

The above indicative list is not exhaustive.


Using the data

How do I get the Census flow data?

The Flow Data website provides three routes to the data.

  • WICID is the main route to the flow data. It provides a flexible service to download extracts of data in a variety of forms
  • Downloads is the page which allows a user to download bulk tables as released by ONS, as well as download SASPAC files
  • Flow summaries report the largest flows associated with a chosen location
  • Off the shelf data sets are available for some of the more common queries

I have access to the safeguarded data. What are the conditions of use of safeguarded 2011 census flow data?

  • Users of these data are reminded that these data can be used only for the purposes of not-for-profit research or teaching or personal educational development.
  • The data may be shared with anyone who has registered with the UK Data Service and accepted the terms and conditions stipulated in the End User Licence.
  • Results of analyses which aggregate geographies and/or categories of variable may be shared with anyone, so long as these results are appropriately protected not to identify individuals, households or organisations.
  • Appropriate protection in this case has been deemed by the Data Owners to be the protection of any cell count lower than three. There is no requirement to round – though if users wish to do that, that is their choice. Users could suppress any counts lower than 3, or replace any 1s or 2s by a 0 or 3. These are not prescriptive; users may find other methods more satisfactory.