Gender identity data harmonised standard

This harmonised standard is under development.

Following the Inclusive Data Taskforce recommendations, we plan to review and update the current harmonised standard. This is in line with the Government Statistical Service (GSS) Harmonisation Workplan.

The GSS harmonisation team are restructuring to embed elements of their work into the future of population and migration statistics transformation work. This strategic move is part of the wider business planning at the Office for National Statistics (ONS) and will position and prioritise the central harmonisation resource at the centre of the future population and migration system.

The GSS harmonisation team are currently prioritising research to update the ethnicity standard. The team’s plans for ethnicity and other priority areas will be updated once the ONS’ public consultation on the future of population and migration statistics in England and Wales has concluded. This will allow the ONS time to review this source of relevant responses from users about their needs. This information will also be used to inform their future research plans.

You can find more information about this in the “Further information” section of this page. If you would like to be involved with this work, please contact us at

Policy details

Metadata item Details
Publication date:16 July 2020
Owner:GSS Harmonisation Team
Who this is for:Users and producers of statistics
Type:Harmonisation standards and guidance

What we mean by harmonisation

Harmonisation is the process of making statistics and data more comparable, consistent, and coherent. This harmonised standard sets out how to collect and report statistics to ensure comparability across different data collections in the Government Statistical Service (GSS). This produces more useful statistics that give users a greater level of understanding.

Who this standard is for

This standard is for researchers who are thinking about including a question about gender identity on their surveys or in their administrative data collection.

This harmonised standard will be useful to people in government departments and the wider public sector who are thinking about the best way to collect data on gender identity.

Why we collect gender identity information

Data are needed for policy development, and for service planning and provision.

There is also a growing need for respondents to be able to record an identity other than “male” or “female” on surveys or forms.

There is not much official data on the topic of gender identity at the moment.  You can find a summary of research into existing data on gender identity and sexual orientation on the Office for National Statistics (ONS) website. The ONS research found that few surveys currently collect gender identity data, specifically information about people whose gender identity is different from their sex registered at birth. This is a relatively new topic, so there are limited statistics or data available from the surveys that do collect this information.

ONS will be publishing Census 2021 figures on gender identity in early 2023. This is the first time this information has been collected in the England and Wales Census.

There is no agreed best practice for collecting gender identity data yet. Collecting gender identity data in a consistent manner will help build the evidence base. This would help to bring an awareness of the size of the population whose gender identity is different from their sex registered at birth, their needs and access to specific services, and inequalities these people may be facing.

Questions and response options (input)

The current gender identity data harmonised standard is currently ‘under development’. It has been designed to meet stakeholder needs by collecting two pieces of information:

  1. Whether a person’s gender identity is the same or different from their sex registered at birth – this is captured using the “Yes” or “No” response options.
  2. How people wish to self-describe their gender identity – this is captured using the free-text box.

This standard is about gender identity. It does not collect information on sex. You can find more information on the collection of data relating to sex on the sex and gender harmonisation guidance webpage.

English language self-complete question


Is the gender you identify with the same as your sex registered at birth?

Response options

  • Yes
  • No, enter gender identity
  • Prefer not to say

Welsh language self-complete question


Ydy’r rhywedd rydych chi’n uniaethu ag ef yr un peth â’r rhyw a gofrestrwyd pan gawsoch chi eich geni?

Response options

  • Ydy
  • Nac ydy, nodwch eich hunaniaeth o ran rhywedd
  • Mae’n well gen i beidio â dweud

Using this standard

Age of the respondent

This question has been developed for respondents aged 16 and over.

Free-text option

The inclusion of the free-text option is important because it increases acceptability of the question for members of the trans community. This can lead to them being more willing to answer the question. Further tick-box options have not been included because there are a variety of identities with which people may identify and the language related to this topic is developing.

It is important to remember that detailed information should only be collected if there is a need for it. We encourage you to think about how information collected by the free-text option would be used before using the question.

In our review of the gender identity data harmonised standard we have discussed the limitations of the free-text option and have set out the work we plan to do to address these limitations and move the standard from ‘under development’ to ‘final’.

If you do choose to use the gender identity harmonised standard without the free-text option, please email and share your experiences.

The “Prefer not to say” response option and refusals

Most surveys and administrative collections of data are voluntary. It is good practice to tell people at the start of the data collection that they do not need to answer anything they do not want to answer. This means respondents should be able to skip the gender identity question if they do not wish to answer it.

The gender identity question can be sensitive for some respondents and we must be able to maintain the privacy of respondents. This means that we recommend explicitly providing an option that gives people a way of not having to answer the question. This can be done by offering the “Prefer not to say” option on the standard. This is in addition to the implicit option of refusing to answer the question. This is consistent with good practice in data collection for sensitive topics.

Question placement

We anticipate that a gender identity question may be asked with a question on sex. Some data collectors may want to collect data on the protected characteristic of male or female sex in addition to data on gender identity.

The gender identity question and a sex question can be placed next to each other or apart. Sometimes a respondent will be unable to see that a gender identity question will be asked after the sex question. In these cases, we would recommend adding a guidance note to the sex question to tell respondents that a gender identity question will be asked.

Suitable data collection methods for this standard

The question has been developed primarily for self-completion on paper and online.

Guidance for data collection

How and where people will answer the questions

Privacy is an important issue in answering a question about gender identity, which is considered a personal matter.

If you are asking the question in a face-to-face context, aim to ensure respondents’ answers cannot be seen by others. For example, if you will be asking the question as part of an interviewer-led household survey, respondents could be offered the chance to complete the gender identity question themselves. This would enable them to keep their response private from the household and the interviewer.

Proxy response, or completing the question on behalf of someone else

As is good data collection practice, you should aim to get an answer directly from the respondent themselves wherever possible. This is part of good data collection practice, and we would recommend this for the collection of gender identity information.

The topic of gender identity is sensitive and private. You should carefully consider whether it is appropriate to enable proxy response. We advise putting in place appropriate ways to maintain privacy and protect respondent confidentiality.

The ONS found that gender identity information can be collected by proxy if needed, but you should be aware that this may affect the quality of data collected. You can find out more about the ONS findings on proxy responses to the gender identity question on the ONS website.

The testing of proxy response was in relation to Census 2021 for England and Wales. In this case, people will be able to respond independently from the household questionnaire, with the individual response overriding household response. The ONS has not tested acceptability of proxy response in the context of general surveys and administrative data collections. These cases may be different.

The Northern Ireland Research and Statistics Agency (NISRA) currently ask a gender identity question in some of their household surveys. But it is important to be aware that proxy responses to the question are not permitted.

Presenting and reporting the data (outputs)

Recommended data presentation

In the table [data] represents where data should be inserted.

Gender identity the same as sex registered at birth [data]
Gender identity different from sex registered at birth [data]
Prefer not to say [data]
Spontaneous only: refusal or did not answer [data]

How to categorise responses into the data presentation template

Gender identity the same as sex registered at birth

This refers to people who selected “Yes”. It includes male when registered male at birth and female when registered female at birth.

Gender identity different from sex registered at birth

This refers to people who selected “No” and whose gender identity is not the same as the sex they were registered at birth. This is inclusive of a range of gender identities, including:

  • binary male or female genders when not the same as registered at birth
  • non-binary genders such as those on a continuum between male and female
  • non-gendered identities, which are neither male nor female

Prefer not to say

This refers to people who responded with “Prefer not to say”.

Spontaneous only: refusal or did not answer

This refers to people who have either refused to answer the question, or more generally, did not give a response. This should not be presented as an option to the respondent, but it can be recorded. This is useful to infer the acceptability and usability of the question and will help us evaluate the standard while it is under development.


We aim to harmonise data collection and outputs across the United Kingdom (UK) where this is appropriate. But needs and circumstances sometimes differ between the countries.

We encourage researchers to use the harmonised standard for collecting gender identity data.  If researchers use this question in a UK-wide context they should be aware that data collected may not be fully comparable with country-specific official statistics.

Data collection across the UK

England and Wales

Census 2021 for England and Wales

The ONS is responsible for the census in England and Wales. Census 2021 in England and Wales included a gender identity question. The Census (England) Regulations 2020 and Census (Wales) Regulations 2020 both came into force in June 2020. The development of the question was informed by research and testing. It has been found to meet user needs identified for England and Wales. The question is available in both English and Welsh.

As this harmonised standard is based on the gender identity question for Census 2021 for England and Wales, data collected will be broadly comparable.

Crime Survey for England and Wales

The Crime Survey for England and Wales, conducted by Kantar on behalf of the ONS, has been trialling a gender identity question in a self-completion module on the questionnaire, as part of the face-to-face interviews. The question in the Crime Survey is based on the question that was used in the 2019 Rehearsal for England and Wales for Census 2021, with the addition of “Prefer not to say” and “Do not wish to answer” response options.


Scotland’s Census 2022

The National Records of Scotland (NRS) are responsible for the census in Scotland. The Census (Scotland) Regulations 2020 came into force in June 2020. Scotland’s Census 2022 included a question on trans status and history. Their testing showed this question was acceptable in Scotland and produced good quality data.

You can find information on this testing in the NRS Sex and Gender Identity Topic Report.

Northern Ireland

Census 2021 in Northern Ireland

The Northern Ireland Research and Statistics Agency (NISRA) are responsible for the census in Northern Ireland. NISRA did not ask a question on gender identity in their Census 2021 due to a limited user need for a question on gender identity.

Household surveys

NISRA currently ask a gender identity question on some of their household surveys, which include:

The GSS Harmonisation Team will work closely with ONS, the Welsh Government, NRS and NISRA as part of the ongoing development process for the harmonised standard, and also to provide comparable Census 2021 outputs where possible.

Development of this standard

We have developed a question to collect data on those whose gender identity is different from their sex registered at birth. This question was developed as a priority. This harmonised standard uses the comprehensive research and testing that was done for Census 2021 in England and Wales.

This is the first gender identity data collection standard to be shared. It should be used primarily in online and paper self-completion contexts. This standard is still under development and future work we plan to do to develop the standard can be found in our review of the current standard.

We are aware that further questions and guidance may be needed for specific situations.

Further information

ONS work related to gender identity

You can find further information about the ONS work in relation to gender identity:

This work includes research and testing, and information about developing a question for Census 2021.

Inclusive Data Taskforce and GSS Harmonisation Workplan

In October 2020, the National Statistician established the Inclusive Data Taskforce. It was designed to improve the UK’s inclusive data holdings in a broad range of areas. This includes the nine protected characteristics of the Equality Act.

In September 2021 the Taskforce recommendations were published. Some of these recommendations specifically refer to harmonisation.

In response to the recommendations, the Office for National Statistics (ONS) oversaw the publication of an Inclusive Data Taskforce Implementation Plan in January 2022. This gives information about the current and planned initiatives across the UK statistical system. It refers to a GSS Harmonisation workplan, which was published in February 2022. This workplan includes reviewing, refining, and updating harmonised standards.

We have published a review of the current gender identity data harmonised standard. This details the strengths and issues of the standard and sets out our future work to develop the standard.

The workplan sets out activities related to the topics of sex and gender identity. These include:

  • changing the gender identity standard from ‘under development’ to ‘final’
  • analysing Census 2021 write-in responses for the gender identity question
  • publishing more guidance to help people use the questions – for example, more guidance will be needed for interviewer-led modes
  • updating our sex harmonisation guidance by early 2023 to reflect a suite of existing technical guidance for data collectors
  • testing possible improvements and changes to question design as needed
  • explore the feasibility of including a list of gender identities as a closed question
  • undertaking stakeholder engagement – this includes a survey for data users exploring administrative data to better understand how data is collected in administrative datasets for sex

Timescales for this work will be guided by the testing that we plan to do and our engagement with stakeholders and respondents. We are now working to:

  • update our sex harmonisation guidance by early 2023 to reflect a suite of existing technical guidance for data collectors
  • publish guidance on using the questions in interviewer-led modes in Summer 2023
  • publish an updated gender identity standard with further guidance in Autumn 2023
  • run research activities throughout winter 2022 and 2023

If you would like to be involved with this work, please contact us at

Contact details

You can contact the Government Statistical Service (GSS) Harmonisation Team by emailing

You can contact the Gender Identity and Sexual Orientation Team at the Office for National Statistics (ONS) by emailing

You can find more information about the ONS work on this topic on the ONS website.

Review frequency:

This standard is under development. We will monitor its use and provide updated guidance in due course.


Date Changes
15 December 2022 We have updated this webpage with information and links to our review of this gender identity standard.
22 April 2021 The wording of the Welsh gender identity question was updated slightly to match the agreed wording for the Census paper questionnaire.
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