Important Information
About this guidance
The Office for Statistics Regulation (OSR) is the independent regulator of official statistics produced in the UK. We work to ensure that data and statistics serve the public good and meet society’s needs for information. Through the standards of Trustworthiness, Quality and Value set out in the Code of Practice for Statistics (the Code), we support producers to develop and deliver statistics that meet the needs of users and are accompanied by supporting information to aid the appropriate interpretation of the statistics.
This guidance is intended to support official statistics producers in applying the principles of the Code when making decisions about the collection and reporting of statistics and data about sex and gender identity. While the guidance is aimed at official statistics producers, others working with data and statistics, both inside and outside government, may find it helpful.
Official statistics producers regularly collect and publish information on sex. In recent years, some statistics producers have started, or are considering, collecting information on gender identity to address previous data gaps in the statistics or to allow data to be collected which recognise how a person identifies.
This is a complex area that is evolving in our society, and where public understanding may vary. In this context, statistics producers face challenges in their engagement and in making decisions about data collection and reporting. This is hindered by the absence of harmonised definitions of sex or gender identity for official statistics production in the UK, and the fact that survey respondents and data users may have their own interpretation of the terms being used.
All official statistics producers are responsible for ensuring that their statistics continue to be useful, easy to access, remain relevant and support understanding of important issues. Applying this guidance should not be seen as a one-off activity; rather, it should be continuously applied to support ongoing development and improvements.
We consider this guidance to be relevant regardless of whether the data are collected through surveys or administrative data systems. Both these collection types are considered within this guidance, and each has different considerations and complexities for statistics producers to take account of.
For further advice or additional support on the production of their statistics about sex and gender identity, producers should consult their Head of Profession for Statistics, Chief Statistician or Lead Official for Statistics.
How this guidance should be used
Each section of this guidance addresses a typical stage in the production of official statistics. Within each section, we have set out our expectations for statistics producers and key questions that they should consider. While understanding the needs of users of statistics is presented last within this guidance, we consider this to be a central factor in each of the preceding stages.
This guidance is for individuals and teams who are directly involved in statistical production. Our expectation is that this guidance will be used to ensure that statistics producers have a strong understanding of what data they are collecting and how their data collections meet the needs of their users and respondents, and that statistical information is communicated clearly and transparently to statistics users.
Heads of Profession for Statistics, Chief Statisticians and Lead Officials play a key role in leading work in this area. These officials are responsible for advising statistical and analytical teams on statistical practices, making decisions on approaches and ensuring coherence across outputs whenever possible. We expect them to use and promote this guidance within their departments.
We encourage all statistics producers to engage with existing professional networks and to consider developing new networks in order to share best practice and learn from others.
Terminology used in this guidance
The Code states that data sources should be based on definitions and concepts that are suitable approximations of what the statistics aim to measure, or that can be processed to become suitable for producing the statistics.
Currently there is no single definition of sex or gender identity within the official statistics community. We also recognise that respondents and users may have differing interpretations of these terms. Given this, it is vital that producers clearly define and explain any terminology that they are using. It is the responsibility of statistics producers, rather than OSR, to decide on and explain the definitions used within any data collections and statistical outputs.
This guidance does not set out harmonised standards for sex or gender identity definitions, as this is not within our remit as a regulator. We have, however, looked at how sex and gender identity have been defined within guidance published by other organisations. To provide a framework for using this guidance, we have set out our interpretation of these terms. We recognise that there will be differences in how familiar people are with the terms, that some people may prefer to use alternative terms than those set out below and that some people may feel that certain terms do not apply to them.
When we use the term ‘sex’ in this guidance, we are referring to a binary variable categorised as female or male. In the UK, an individual’s legal sex is recorded at birth based on their biological characteristics. Individuals over the age of 18 can apply for a Gender Recognition Certificate (GRC), which enables them to change their legally recognised sex, including on their birth certificate. Where an individual has a GRC, their legally recognised sex may differ from their sex recorded at birth.
When we use the term ‘gender’ in this guidance, we are referring to the socially constructed characteristics and behaviours of men, women, boys and girls. The concept of gender is not fixed and can vary from society to society and change over time. We acknowledge that there are different interpretations of ‘gender’ and that the history of this term is complex. In addition, within official statistics data collections, the term ‘gender’ has often been used interchangeably with ‘sex’.
When we use the term ‘gender identity’ in this guidance, we are referring to an individual’s innate sense of their gender. Gender identity is not constrained to the binary male/man and female/woman categories and includes others such as non-binary and gender fluid. For some individuals, their gender identity may be different from their sex recorded at birth, and/or from their legally recognised sex.
When we use the term ‘transgender’ in this guidance, we are referring to individuals whose gender identity is different from their sex recorded at birth. Some statistics producers are currently collecting, or may be considering collecting, information on an individual’s trans status or trans history. This guidance does not explicitly cover this approach to data collection. However, we consider that many of the principles of this guidance are still useful and applicable.
Producers should be aware that an individual can change their sex on some documents to reflect their gender identity without changing their legally recognised sex with a GRC. These documents include a driving licence, a passport, medical records, employment records and a bank account. Statistics producers should account for this when they are producing definitions and providing guidance to respondents on how they should answer questions on sex or gender identity.
Using terminology interchangeably
We recognise that the terminology in this topic area is evolving, which can be a challenge for statistics producers. As a result, some producers may currently be using terminology that does not accurately reflect what they are trying to collect and report data on. This underlines the importance of clearly defining and explaining the terms being used, as well as not using terms interchangeably or as substitutions for each other.
Through our work, we have seen instances where there is a lack of consistency and clarity around the term ‘gender’, both in data collection and in statistical reporting. In some cases, it is not clear whether producers are using the term gender as a substitution for sex or gender identity. For example, producers may collect data about sex, yet report statistics on the basis of gender. Alternatively, producers may ask a question on gender with the intention of collecting data about gender identity, but only provide binary response options of male/man and female/woman. This conflation of terms lacks clarity for respondents and users regarding exactly what data are collected and may affect the quality of the data reported.
We recommend that statistics producers who collect and report ‘gender’ should consider what they mean by this term and whether it accurately reflects what they are trying to measure. This should be clearly communicated to respondents and users of the statistics.
OSR programme of work on sex and gender identity
This work forms part of a broader OSR programme on data about sex and gender identity. As part of this programme, we undertook a review of gender identity in the 2021 England and Wales Census. We published an interim report on 9 October 2023 and a final report on 12 September 2024. The publication of this final report concluded our review.
Learning from new evidence in Scotland’s Census, the Office for National Statistics (ONS) wrote to us on 5 September 2024 to request that the gender identity estimates from Census 2021 should no longer be accredited official statistics and should instead be classified as official statistics in development. We wrote to ONS to support its proposal.
Our final report sets out the details of our regulatory decision and shares our recommendations to ONS on the steps it must take to help users of the census gender identity statistics understand their strengths and limitations. In addition, we set out the development work we consider is required on the Government Statistical Service (GSS) gender identity harmonised standard. Our recommendations include that, as part of the ongoing development of the GSS harmonised standard for gender identity, ONS should carry out further testing of the question and that the GSS publish advice for statistics producers who are currently using the gender identity question and for those who are thinking about adopting the standard.
We found that the issues highlighted in our final report were unique to the statistics on gender identity and therefore that all other outputs from the Census 2021 in England and Wales are unaffected by the decision and remain designated as accredited official statistics.
Questions used to collect data about sex and gender identity
It is important that the collection and reporting of data about sex and gender identity is based on users’ needs for data and statistics. How those data are captured will depend on various factors, including the questions asked to survey respondents and the related guidance, or the data required for administrative systems. Different approaches can be taken in designing questions to collect these data, and – while we support producers taking account of comparability, data quality and respondent acceptability – ultimately it is the decision of the statistics producer or producer organisation as to exactly which questions and what guidance are used.
The Government Statistical Service (GSS) is responsible for providing information to producers on harmonised standards for data collection. These include definitions, survey questions and suggested presentations for users.
Acting on the recommendations set out in the final report of OSR’s review of gender identity in the 2021 England and Wales Census, the GSS Harmonisation Team, based in the Office for National Statistics (ONS), has commenced a new phase of work towards agreed harmonised standards for sex and gender identity data collection. Sex harmonisation guidance and new Gender Identity Data Harmonisation interim guidance are available for producers of statistics who are currently using, or thinking about including, a gender identity question on their surveys or in their administrative data collection. OSR will continue to engage with the GSS Harmonisation Team and with statistics producers regarding this work.
The Scottish Government has published guidance for public bodies on the collection of data on sex and gender, Sex, gender identity, trans status – data collection and publication: guidance, which includes a section on questions.
Our guidance does not assume a particular question set is used to collect data about an individual’s sex and gender identity. This guidance remains relevant in its application of the principles of the Code regardless of the questions used to collect these data.
Proportionality
Proportionality in data collection
We recognise that the statistical landscape is complex, and that producers will be balancing competing priorities and available resources. We consider that the level of work undertaken to decide whether to make a change to the existing collection of data about sex, or to introduce a collection of gender identity data, should be proportionate to the importance of this information to the users of those statistics. This same principle applies to the collection of this information, where the burden imposed on those providing their data should be proportionate to the benefits.
For some statistical outputs, it will be important to capture information that would be unique to either sex or gender identity, for example, when statistics aim to understand the service provision or experiences of a particular group of individuals. In these instances, it is vital that producers make informed decisions about what to collect. For other statistical outputs, there may not be a clear need to collect a specific type of information and the decision may not affect the usability of the data. In either scenario, producers should ensure that they are using clear and considered definitions and that these are explained to respondents and users of the statistics wherever possible.
We acknowledge that it may not be possible for producers to apply all the principles of this guidance to their data collection. Producers should aim to balance considerations of best practice; data quality; user and respondent needs; the extent of possible system changes; and the required resource. Regardless of the extent to which producers are able to apply this guidance, producers should always be open and transparent about their practices, decision making and the level of understanding of what data are being captured and how. This transparency will ensure that users are supported in the interpretation and use of the resultant statistics.
Producers should be proportionate when applying the principles of this guidance to their data collections based on the nature of their statistics and the needs of their users.
Proportionality in data use
For a large proportion of the population, an individual’s sex and gender identity will be aligned. For a considerably smaller proportion of the population, an individual’s gender identity is different from their sex as recorded at birth or their legally recognised sex.
Given the current varying approaches to collecting data about sex and gender identity across the statistical system, there will be times where producers or users are analysing data based on different approaches or on collection methods that did not have clearly defined terms or guidance for respondents. Users should also be aware that even if definitions and guidance have been provided to respondents, it is possible that respondents will have their own interpretations and may have answered questions differently. Datasets may therefore contain a combination of data about sex or gender identity.
In these circumstances, producers should seek to understand what data are actually being captured and evaluate the impact of the approach on the interpretation of the statistics. This information should be clearly communicated to users as well as any associated limitations.
Clear information on what has been collected is important where users are looking to conduct specific analysis. These users should be made aware of any limitations that may affect their analysis. Where key variables of interest are unlikely to vary significantly by sex or gender identity, producers and users of the data should have confidence in conducting high-level analysis and drawing conclusions.
Legal requirements
The Code clearly sets out that all statutory obligations governing the collection of data, confidentiality, data sharing, data linking and release should be followed. Producers should familiarise themselves with any legal requirements and guidance that apply to the data and statistics they are collecting and publishing.
Where relevant, producers should ensure that they are adhering to the Equality Act 2010, including the Public Sector Equality Duty for England, Scotland and Wales, and the Section 75 duties for Northern Ireland. Producers should be aware that sex and gender reassignment are protected characteristics as set out in the Equality Act 2010.
Producers should also ensure that they are adhering to the principles set out in the General Data Protection Regulation (GDPR), including data minimisation. Producers should be aware that information about an individual’s transgender status may be considered as special category data in some circumstances. Special category data must be treated with greater care than other types of personal data and can only be processed if one of the specific conditions in Article 9 of the UK GDPR is met (see the Information Commissioner’s Office (ICO) guidance on lawful basis on processing special category data).
It is not within OSR’s remit to determine the requirements of relevant legislation or whether they are being adhered to. Producers should consult their legal advisors and, where necessary, liaise directly with relevant bodies, such as the Equality and Human Rights Commission (EHRC), Equality Commission for Northern Ireland or the ICO, in order to ensure that data collections are fully compliant with legislation.
Additional information
In 2021, the Inclusive Data Taskforce published a report on how the government can be more inclusive in its data. This report includes recommendations on how best to make a step-change in the inclusivity of UK data and evidence. Many of these recommendations relate to the collection of information on sex and gender identity, either directly or indirectly. We encourage producers to familiarise themselves with the report and consider how they can contribute to the aims set out.
For support on any ethical considerations related to the use of data, we recommend producers visit the UK Statistics Authority’s Centre for Applied Data Ethics website for further information.