Sexual orientation is a protected characteristic in the United Kingdom under the 2010 Equality Act. It is composed of three dimensions: identity, attraction and behaviour. Office for National Statistics (ONS) has collected information on sexual identity since 2011. In 2015, 1.7% of the UK population identified as lesbian, gay or bisexual. However, this estimate could be higher.

ONS is considering making a recommendation in the 2018 Census White Paper that a sexual identity question is included on the 2021 Census. The recommendation is based on our 2021 Topic Consultation identifying a strong need among data users for information on sexual identity in relation to equalities monitoring, policy development, service provision, and measuring social outcomes.

Our recommendation has been informed by evidence from a wide range of research including a public acceptability survey and 2017 Census Test.

Our public acceptability research shows that a voluntary sexual identity question is acceptable and the public would provide an accurate answer to the question. Moreover, analysis of the 2017 Census Test which was a split samples test of 100,000 households (half of the sample received a sexual identity question and the other did not) shows that a sexual identity question did not negatively impact on the survey response. The overall response from the sample with a sexual identity question was about 1 percentage point lower to the sample without the question which is within our threshold. These findings will inform our recommendation in 2018 for the inclusion of a sexual identity question on the census.