Our work on data about sex and gender identity

The Office for Statistics Regulation (OSR) is currently working on a number of topics regarding data about sex and gender identity.

This page was last updated on 29 February 2024

Guidance on data and statistics about sex and gender identity

On 29 February 2024, we published new guidance on collecting and reporting data about sex and gender identity in official statistics. This updates and supersedes the OSR previous draft guidance on collecting and reporting data about sex in official statistics, published in 2021.

The guidance provides producers of official statistics a set of tools, based on the standards of the Code of Practice for Statistics, to help them think through how they collect and report data about sex and gender identity.

The key message of this guidance is that official statistics producers should have a strong understanding of their own data collections and how these meet the needs of their users, that producers should be clear about what information they are collecting and why, and explain this information as straightforwardly as possible both to respondents and data users.

To develop this guidance, we engaged with official statistics producers across the UK and a range of external stakeholders. This feedback, coupled with the insights from our regulatory work, helped to shape the guidance to ensure it supports the collection, use and communication of statistics in this area. We would like to thank all of those who shared their views with us.

We recognise that this is an evolving area, and we will keep this guidance, including the case studies, under review and update when appropriate. We welcome feedback on this guidance from statistics producers and others at any time – please email regulation@statistics.gov.uk.

Review of Gender Identity in the 2021 England and Wales Census

This section updates on our ongoing review of statistics on gender identity based on data collected by the Office for National Statistics (ONS), as part of the 2021 England and Wales Census.  


Our review is formed around the Code of Practice for Statistics and will consider ONS’ approach to responding to questions raised by users about the results of the data. It will not consider gender identity as a concept or the decision to collect data on gender identity. 


The first release of statistics by ONS on gender identity based on data collected in the 2021 Census was in January 2023. Following this publication, we received concerns regarding the correlation of gender identity with other characteristics, as well as the level of methodological information published on how the gender identity question has been processed. We reviewed these concerns through our casework process and wrote to ONS on 24 April advising it that we were undertaking a short review of the gender identity data. 

On 19 June ONS published an article which provided additional information on the methodology for collecting and processing data on gender identity in Census 2021. Upon publication of this article, we wrote to ONS to welcome the additional information and to share our emerging findings from our review. ONS had committed to publishing further information in summer 2023 to provide greater insight into the data.  On 30 August ONS released a statement advising that this research is ongoing and that it will publish further updates in due course.

OSR interim report

We published an interim report on 9 October. The report sets out our findings based on OSR’s review of the testing, quality assurance, communication and engagement with users undertaken by ONS. 

ONS has now published its research and we will publish a follow up report with our findings after we have reviewed, and engaged with users on, the full set of research. 

If you want to share your perspective as part of our review, please contact us.  

OSR Review Correspondence