Religion harmonised standard

Policy details

Metadata item Details
Publication date:10 September 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. Harmonised standards set out how to collect and report statistics to make sure they can be compared effectively across different data collections in the Government Statistical Service (GSS). Harmonisation produces more useful statistics that give users a greater level of understanding about a topic.

What we mean by religion

Religion can include different concepts like affiliation, practice, and belief. Where a single question on religion is needed for data collection in the UK, religious affiliation is the recommended concept.

The Office for National Statistics summarises the different dimensions of religion in a Census 2011 development report. It is generally understood that surveys can measure three different dimensions of religion depending on the question that is asked. The three dimensions are affiliation, practice, and belief.

Religious affiliation

Religious affiliation can be defined as “a present or past personal or familial connection” with a religion. There are two measures of affiliation:

  • ‘weak affiliation’ – this could be understood as community affiliation
  • ‘strong affiliation’ – this may relate to membership

We can explain the differences by using Christianity as an example.

Weak affiliation

Members of the Christian community who have ‘weak affiliation’ with the religion are defined as people who positively identify as belonging to a church, even if they rarely attend or were just baptised as a child. They may have no current connection with the church.

Strong affiliation

Each Christian denomination has a different way of defining ‘strong affiliation’ with the religion. For example, you must have been baptised to be a member of a Christian Baptist church.

Questions about religious affiliation

Questions on religious affiliation are suitable for gaining a broad understanding of how an individual identifies the depth of their own religious feelings. They are appropriate for use in most surveys and can give a high-level indicator about religion.

Religious practice

Religious practice includes specific religious activities that are expected of believers “such as worship, prayer, participation in special sacraments, and fasting”. It is a difficult concept to measure because there are no specific actions that will be relevant across all religions. For example, it may not be relevant to measure frequency of attendance at place of worship or frequency of prayer if this is not an essential feature of a particular religion. For these reasons, a broad question such as “Do you consider yourself to be currently practising?” may not intend to introduce cultural bias, but it is likely to be interpreted in different ways. None of these measures will record the significance of the religious practice to a person’s life.

Questions on religious practice are useful if the user wants to collect data on a about a specific reference or activity.

Questions about religious practice are also useful if the user wants to understand more about the frequency of religious activities to work out how this is connected to the depth of a person’s religious feelings. But this can be inaccurate, as there may be other variables which affect religious practice, such as ability or access. These questions would generally be used if a more detailed understanding of religion was needed.

Religious belief

Religious belief includes beliefs that are expected to be held by followers It also refers to an element of the importance of religious beliefs to a person’s life. The words ‘belief’ and ‘faith’ tend to be used to mean the same thing. As with affiliation, there can be strong and weak forms of belief.

Questions on religious belief may be useful to gain greater understanding of specific beliefs. They would generally be used if a more detailed understanding of religion was needed.

The term ‘belonging’ is also found in literature on religion, and it is used in different ways. For example, it can be used in relation to affiliation, or passive belonging based on self-identification. It can also be used in relation to regular churchgoing, or active belonging.

Religion is a protected characteristic. This means it is against the law to discriminate against someone because of their religion, or lack of religion.

Questions and response options: inputs

The harmonised questions on this topic are designed to collect basic information. They can be used in most surveys. They are not designed to replace questions used in specialist surveys where more detailed analysis is needed.

The questions

The harmonised questions and response options for this topic are UK-country specific. This means that there is an individual question for each of the UK countries to suit the demands of that country.

The question stem for England is: “What is your religion?”.

The response options are:

  1. No religion
  2. Christian (including Church of England, Catholic, Protestant and all other Christian denominations)
  3. Buddhist
  4.  Hindu
  5. Jewish
  6. Muslim
  7. Sikh
  8. Any other religion, please describe

The question stem for Wales is: “What is your religion?”.

The response options are:

  1. 1. No religion
  2. Christian (all denominations)
  3. Buddhist
  4. Hindu
  5. Jewish
  6. Muslim
  7. Sikh
  8. Any other religion, please describe

The question stem for Scotland is: “What is your religion?”.

The response options are:

  1. No religion
  2. Church of Scotland
  3. Roman Catholic
  4. Other Christian
  5. Buddhist
  6. Hindu
  7. Jewish
  8. Muslim
  9. Sikh
  10.  Any other religion, please describe

The question stem for Northern Ireland is: “What is your religion?”.

The response options are:

  1. No religion
  2. Catholic
  3. Presbyterian
  4. Church of Ireland
  5. Methodist
  6. Baptist
  7. Free Presbyterian
  8. Brethren
  9. Protestant – Other, including not specified
  10. Christian – Other, including not specified
  11. Buddhist
  12. Hindu
  13. Jewish
  14. Muslim
  15. Sikh
  16. Any other religion, please describe

Using this standard

Collecting data on cultural identity is complex. This is because the concept of identity is multi-faceted and means something different to everyone.  People’s thoughts about cultural identity tend to change in the context of social and political attitudes or developments.

To allow respondents to properly express their cultural identity, we recommend that the three relevant questions are asked together:

  • national identity
  • ethnic group
  • religion

This provides a more comprehensive understanding of a person’s cultural identity. It will also help us form a more accurate idea about the population.

We recommend that the topics should be ordered:

  1. national identity
  2. ethnic group
  3. religion

Guidance for data collection

We recommend that you use a showcard in interviewer-led surveys in Wales, Scotland and England. Where possible the interviewer should read the question and response options out loud. Showcards should include the instruction ‘please describe’ after the ‘Any other religion’ response option. This instruction should not be in a bold font.

In telephone interviews, or any other survey where showcards cannot be used, the interviewer should read the response options in the same order as the harmonised standard.

Showcards should not be used in Northern Ireland. Instead, the interviewer should read the question and wait for the respondent to give their own spontaneous response.

If the respondent does not give an answer, the interviewer may prompt them by using the response options for Northern Ireland in the harmonised standard.

Types of data collection this standard is suitable for

This harmonised standard is for:

  • self-completion surveys
  • interviewer-led surveys
  • telephone surveys

Presenting and reporting the data: outputs

If you are presenting data separately for England, Scotland, Wales, or Northern Ireland, you should give the data in the same order as the response options in the religion question.

In the table [data] represents where data should be inserted. If presenting data for religion in Great Britain and the UK the data should be presented as follows:

Religion Data
No religion [data]
Christian [data]
Any other religion [data]


Outputs that use this standard are comparable with other surveys that also use this standard. We would not recommend comparing religion outputs using this standard with other outputs that use a different measure.

Surveys that use this standard

A review in 2022 identified surveys that follow the religion harmonised standard. These included:

  • Assets Survey (2016/2018)
  • Crime Survey for England and Wales (2019/2020)
  • Family Resources Survey (England and Wales, 2019/2020)
  • Labour Force Survey (England and Wales, 2021)
  • Millennium Cohort Study (England and Wales, 2018)
  • National Survey for Wales (2021)
  • Scottish Crime and Justice Survey (2019/2020)


England and Wales Census 2021

An initial review of the current harmonised standard on religion and the Census 2021 religion question for England and Wales suggests  that the questions are generally comparable with each other.

The first difference is the voluntary statement that accompanies the religion question in the 2021 Census question. The statement reads “The question is voluntary”. This statement is not in the harmonised standard. This is because it could be read as an indicator that other questions on the surveys which use the statement are mandatory. This is not the case in many data collections which use the harmonised standard.

The second difference is the wording that follows the “Any other religion” response option. The Census 2021 self-complete online question explains that respondents can “enter [their] religion on the next question” when selecting this response option. Meanwhile the harmonised standard says, “please describe”. These changes have been made to account for different survey modes. The changes do not affect comparability between those who want to compare data collected through the religion harmonised standard and the England and Wales Census 2021 religion question.

The England and Wales Census 2021 question stem underpins the current harmonised standard on religion. The question stem is “What is your religion?” and it has not changed from the 2011 Census question stem. This means that the question stems from the census and the current harmonised standard align with each other, and both questions concentrate on the concept of religious affiliation.

Religious affiliation refers to how respondents connect or identify with a religion. It does not matter whether they actively practice their religion by doing things like regularly attending religious services, or not. They can still answer the question about the religion they belong to. This kind of question is considered a ‘weak affiliation’ question.

Northern Ireland Census 2021 and Scotland’s Census 2022

The question text used within the current harmonised standard on religion is not comparable with the religion question text used in the 2021 Census for Northern Ireland and the 2022 Census for Scotland. These censuses ask different religion questions.

Northern Ireland question stem

The questions in the Northern Ireland Census 2021 were:

  • “What religion, religious denomination or body do you belong to?”
  • “What religion, religious denomination or religious body were you brought up in?”

Scotland question stem

The question in Scotland’s Census 2022 is: “What religion, religious denomination or body do you belong to?”

Comparison with the harmonised standard

The question “What religion, religious denomination or body do you belong to?” shares similarities with the affiliation aspect of the harmonised standard. But it places more emphasis on being an active or formal member of a religious group, which indicates ‘strong affiliation’ to a religion. This is different to the harmonised standard, which concentrates on weak affiliation.

The second Northern Ireland religion question ‘“What religion, religious denomination or religious body were you brought up in?” explores a different aspect of religion entirely. It is designed to accommodate people who select the “No religion” tick box in the first religion question. This allows respondents to indicate whether they were brought up according to a certain religion, but have chosen to identify with no religion later in life. This should not affect comparability with data from Scotland’s Census 2022 because a question on belonging is still asked.

Strong and weak affiliation

The harmonised standard uses a weak affiliation question, like the question from the England and Wales Census 2021. This is because strong affiliation based questions, like the question used in Northern Ireland Census 2021 and Scotland’s Census 2022, may exclude people who are not actively practising their religion. People in this group will connect with their religion in lots of different ways that are all meaningful. This group may also include people with no religious affiliation.

Although the concepts of strong and weak affiliation are similar, there is potential for these questions to lead to different responses.

The question “What is your religion?” suggests ‘wide’ or weak affiliation with a particular religion. During testing for the England and Wales Census 2021 we saw that this ‘weak affiliation’ question prompts responses from people whose practising habits vary from none to frequent. For example, responses may come from people who actively practice a religion, as well as people who chose to declare an affiliation with a particular religion based on other reasons. This could include things like:

  • being christened or baptised
  • being married and choosing to get married in church
  • wanting to get married in a church
  • wanting their children to be raised in a particular faith

A question like “What religion, religious denomination or body do you belong to?” suggests that the respondent has a strong affiliation with their religion and that they regularly practice their faith. Because the question suggests a stronger emphasis on active engagement with a particular religion, testing shows that respondents answer ‘belonging’ based questions according to the religion they have been brought up in, or active participation in a particular faith. Respondents who have a loose religious affiliation can feel excluded by this kind of question and may not give a response, or may give a different response. This explains why data produced using the religion harmonised standard are not comparable with data produced by the question used in the Northern Ireland Census 2021 and Scotland’s Census 2022 religion question.

Philosophical belief

We explored the need for a harmonised standard on philosophical belief to be developed in addition to the current harmonised standard for religion. We did not find a clear user need for a standard on philosophical belief.

We also identified that developing a new harmonised standard on this topic would be complex and challenging because discussions on philosophical belief are continually evolving. Philosophical belief is not yet well established in case law and what constitutes philosophical belief is yet to be clearly and fully defined. For these reasons, there is not currently a harmonised standard on philosophical belief. We will continue to review this need in response to any new developments in this area.

Related harmonised standards


We are always interested in hearing from users so we can develop our work. If you use or produce statistics based on this topic, please contact us at


Date Changes
30 June 2022 This page was updated with guidance on philosophical belief. The standard was also reviewed and the web text updated to improve clarity and accessibility.
2 December 2020 This page was updated with further guidance. This includes the need to use the full suite of cultural identity questions; information about the different dimensions of religion; and information about how different parts of the UK measure religion and the impact of this on comparability.
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