User-need for a sex and gender identity harmonised standard: 16 April 2025 to 9 October 2026

FOI reference: FOI-2026-3789

You asked

Under the Freedom of Information Act 2000, please provide the following information held by the Office for National Statistics, including the Government Statistical Service (GSS) Harmonisation team. Unless stated otherwise, the request covers 16 April 2025 to 9 October 2026. Where documents exist in draft and final form, please provide both. If any part of this request would exceed the cost limit, please tell me which part and advise how it could be narrowed (s16).

(a) Any records identifying government departments, public bodies or other data producers or users that told ONS or the GSS Harmonisation team they needed data on "certificated sex" (sex at birth or as modified by a Gender Recognition Certificate), together with the purpose they gave.

(b) The underlying results (raw or summary tables) of the user-needs exercise reported in Developing sex and gender identity harmonised standards: GSS user needs for a harmonised standard (9 October 2026).

We said

Thank you for your request.

We aim to ensure transparency and inclusivity in our communication and engagement and have collated user needs across multiple rounds of engagement throughout 2025 and 2026. We held five listening events across the UK in Edinburgh, London, Cardiff, Belfast and Manchester between April and May 2025 to hear from data users, statistical producers, and members of the public interested in data and statistics to understand their needs for data on the topics of sex and gender identity. We have included a summary of feedback gathered through the five listening events described previously in the associated download (PDF, 2.3MB), which shows how these findings would feed into different stages of further discovery and alpha work. 

In November and December 2025, we also held a series of online roundtable discussions with data collectors and statistics producers recruited from across the Government Statistical Service (GSS) to gather user needs for sex and gender identity data. In total, 54 GSS colleagues from 31 government departments, devolved governments, and public bodies took part in these events. A further nine colleagues took part in online roundtable discussions in March 2026, focusing on the data user needs of cross-government policy professionals.  The engagement exercises considered the related topics of sex and gender identity. Within those exercises, participants identified a range of needs specifically relating to sex, alongside needs relating to gender identity.  

Participants were informed that they had three working days to withdraw their contribution following the session for any reason. After this point transcriptions were anonymised. This is a standard approach across all of our research, to support open participation while protecting the confidentiality of participants and the organisations they represent. Recordings of roundtables were used for transcription purposes only and deleted within one week of the session. We are therefore unable to link identified user needs to data collectors, statistical producers or government departments. 

We have included the User Needs Log (XLSX, 32.6KB) in the associated download, which provides a list of the user needs captured as part of the cross-government roundtables discussions. Column A provides a high-level summary of the type of user, Column B provides our summary of the user need identified, with Column C providing further insight and detail into this, Column D provides the quote supporting this, and Column E provides the roundtable in which it came from.  

Through our listening events and the cross-government roundtables, user needs were identified to us including: 

• sex and gender identity questions that comply with legal frameworks 

• sex and gender identity questions that are inclusive and allow people to represent themselves in data 

• sex and gender identity data collection questions to be acceptable to respondents 

• views that a number of concepts of sex exist and different concepts may be required in different contexts 

• providing clearer guidance on what concept is being asked in a question 

Based on this, we began developing questions for two target concepts of sex for the purposes of the harmonised standard on sex to meet these combined user needs: 

1. biological sex (sex at birth) aligned with the definition for the purposes of the Equality Act, and 

2. certificated sex (sex at birth or as modified by a Gender Recognition Certificate) aligned with the legal recognition provided by the Gender Recognition Act 

Insights from the Discovery Phase as well as the findings from the respondent testing for the sex question development reinforced the need for questions on both concepts of sex. This was particularly to address acceptability and inclusivity for which different participants found each concept acceptable, dependent on the context in which the question was being asked and the perceived relevance to the research.  

The GSS harmonised standards are not mandated or prescriptive. It is therefore for producers of official statistics and researchers to determine what their user needs are, taking into account the purposes for which the data and analysis will be used, in determining which question, if any, meets their needs on data collection for the topic of sex. Providing questions for two different concepts of sex allows data collectors to consider which question, or concept, may be most appropriate based on their user needs and consider the legitimate need for asking this.