Dear Emma

Thank you for your letter dated 11 December 2024 in which you provided an update on the work the Office for National Statistics (ONS) and the Government Statistical Service (GSS) are taking to address the recommendations set out in our September 2024 Review of statistics on gender identity based on data collected as part of the 2021 England and Wales Census: Final report.

I note that on 26 March 2025 you published a blog which provides further updates on the actions you are taking to meet the recommendations, including more information on how you are gathering insights for harmonised standards on sex and gender identity, and also that you have published, also on 26 March 2025, additional guidance on the appropriate use of the gender identity estimates from Census 2021 in England and Wales and information on the uncertainty associated with them.

Our recommendations focused on the steps that ONS must take to help users of the census gender identity statistics understand their strengths and limitations and on the development work we considered was required on the GSS gender identity harmonised standard. I want to take this opportunity to commend the ONS and the GSS for the significant progress made in addressing these recommendations. For transparency I have considered each recommendation in turn.

Recommendations related to guidance for use of the census gender identity statistics. We consider that these recommendations are now actioned, and I have set out our reasoning below:

• Provide more practical information to help users understand the uncertainty inherent in the data: On 26 March 2025, the ONS published a new research publication that fully meets this recommendation, Additional guidance on the appropriate use of the gender identity estimates from Census 2021 in England and Wales and information on the uncertainty associated with them. This excellent research report includes example use cases at different levels of geography and population and addresses likely anomalies and implausibilities. We are confident this practical information will allow users to better understand the uncertainty in the data and its implications for use.
• Communicate clearly the implications of the change to ‘official statistics in development’. Address the varying levels of information provided across gender identity publications: In response to this recommendation, the ONS has added information and a notice or statement on all the gender identity bulletins, webpages where data tables can be downloaded, and on NOMIS indicating that the statistics are ‘official statistics in development’. All the sources of information clearly direct users to refer to the Census 2021 sexual orientation and gender identity quality information page, which has been updated in March to reflect the additional guidance on uncertainty published on 26 March or directly to the additional guidance itself which advises on uncertainty and appropriate use.
• Consult with OSR as it develops these communications. Thank you for keeping myself and my team updated on your work via your letter of 11 December and more generally through ongoing engagement from the ONS and GSS teams with ourselves.

Recommendations related to gender identity question development. We consider that very good progress is being made to address these recommendations, but that these still remain open.

• Carry out further testing of the gender identity question. I would like to take this opportunity to acknowledge the commitment the GSS has made to further testing of the gender identity question as part of the ongoing development of the GSS gender identity harmonised standard. As outlined in your revised workplan for the topic of Sex and Gender Identity, which was updated on 11 December 2024, your methodology for the work to develop finalised harmonised standards implements Agile Development and Respondent Centred Design. We consider your approach, which is currently in the Discovery phase, and which includes a series of regional events across the UK where you are listening to stakeholder needs for questions and data on these topics, to be commendable.
• Prioritise the work on the gender identity question. The GSS Harmonisation team has published a workplan for the topic of gender identity and is delivering work to the plan. My team in the OSR meets with the team regularly for updates on all harmonisation work.
• Engage stakeholders in future work: Since the publication of the report in September 2024, you have written two blogs on the National Statistician website explaining the work being undertaken. Additionally, the GSS has published a detailed workplan on the topic of Sex and Gender Identity and is now rolling out a series of regional events for stakeholders. The workplan, harmonised standards and your blogs includes details on how people can keep in touch and provides an email contact.
• Publish advice for statistics producers using the gender identity question: On 11 December 2024, the GSS replaced the archived gender identity standard with new interim guidance, Gender identity data harmonisation guidance, for producers of statistics and researchers who are currently using, or thinking about including, a gender identity question on their surveys or in their administrative data collection. As there is currently no finalised harmonised standard for collecting gender identity data, the guidance sets out the gender identity questions used in censuses across the UK, alongside additional information and considerations statistics producers should take when considering how to ask about this topic in their data collection. The guidance also provides information for producers publishing outputs by gender identity. It underscores the need for users to be clearly informed about the uncertainty in the data and its implications for further use. Additionally, the guidance provides recommended text that includes information on the new research outlined earlier in my letter to be included alongside any outputs.
• Consider the gender identity question as part of the Future of Population and Migration Statistics consultation. Please continue to keep me updated on this wider programme of work.

The work you are doing on the development of the GSS harmonised standard for gender identity, including stakeholder engagement, is important for building and restoring confidence with users. Please continue to keep me updated on your progress.

Yours sincerely

Ed Humpherson
Director General for OSR