The 2017 Test was part of our ongoing preparations for the 2021 Census. It gave us the chance to test systems and services, and try out proposed new questions.

13 December 2017 – Test Report

Take a look at our 2017 Test Report to find out what we learned from the test and how we’re using the results.


How the test worked

We invited 100,000 households across seven local authorities in England and Wales to fill in a test questionnaire online.

The invite letters included a unique access code so householders could access the online questionnaire.

Another 108,000 randomly selected households across the rest of England and Wales were also involved. Some of these households received the invite letter and others got a paper questionnaire. Any of the households had the chance to complete the form online, though.

What we tested

We’re planning some changes for the 2021 Census. One of the biggest changes is that it will be mainly online for the first time.

The 2017 Test gave us a chance to make sure our systems and services work correctly before the full census in 2021.

We also tested a proposed new question on sexual orientation. More information about our question development is available.

Where it happened

The local authorities that made up the main test areas were:

  • Barnsley Metropolitan Borough Council

  • Blackpool Borough Council

  • Powys County Council (Cyngor Sir Powys)

  • Sheffield City Council

  • South Somerset District Council

  • Southwark Council

  • West Dorset District Council

We chose these areas because they include:

  • a mix of rural and urban locations

  • some areas with a substantial student population

  • areas with a range of broadband coverage

  • areas with concentrations of ethnic groups

  • multilingual areas

Find out more about how we chose the 2017 Test areas.

The test also sampled 100,000 randomly selected households across England and Wales, as well as 8,000 households on the Isle of Wight.

On the Isle of Wight, we tried out an Assisted Digital service. We designed this service to help people fill in the form online.

Field follow-up

During the test, more than 300 census officers worked across the seven main test areas. They visited households that had not completed the questionnaire to offer help and encourage them to return it.

There were no census staff working in other areas.

Census Test Evaluation Survey

After the 2017 Test finished, we carried out a Census Test Evaluation Survey (CTES). This was a follow-up survey to the test.

We invited a sample of households that were selected for the census 2017 Test to take part. We carried out face-to-face interviews at the homes of any residents who agreed.

Through the CTES, we gathered data to help us gauge people’s understanding, ability, willingness and attitudes towards completing the census test online. These data will help us improve content and the coverage and quality of responses to the 2021 Census.

We carried out the CTES in the same local authorities that were included in the census 2017 Test.