Religion can include different concepts like affiliation, practice, and belief. As a result, a precise definition of the concept of religion, or what constitutes a religion is challenging. Religion may refer to the religious or spiritual beliefs and practices to which an individual adheres or the religious group to which the individual feels they belong.
The CSO Data Standard for Religion considers an individual’s association with a religion regardless of the level of affiliation, belief, practice, or participation in religious activity. It also allows individuals to indicate if they have no religious affiliation.
This harmonised standard presents guidance on how religion can be defined, measured and presented in a more consistent manner.
Data on religion is important for understanding the needs of our diverse population. The data can be used to gauge the level of cultural diversity and equality across society, which is of importance as legislation such as the Employment Equality Acts and Equal Status Acts prohibit discrimination on specific grounds, including religion.
The UN Universal Declaration of Human Rights also refers to religion as a fundamental human right and religion is recognised as one of the nine potential grounds of discrimination under Irish equality legislation.
Some data collections require information on the religion of individuals. When collecting data on this topic, the following question is recommended:
What is your religion, if any?
The standard question on this topic is designed to collect information, for use in the majority of surveys or data collections. However, it is not intended to replace questions already in use for specialist surveys where more detailed analysis is required.
Some statistical production may require more detailed information on religion. In such circumstances, any additional response categories should be based on the standard reference classification. Using the standard reference classification will enable more comparison between surveys, as the definitions and conceptual basis will be consistent.
The following list of response options represents the basic level of detail that the CSO recommends should be gathered in data collection.
| Standard Response Options and Codes for Religion | |
| 10 | No religion |
| 20 | Roman Catholic |
| 30 | Church of Ireland |
| 40 | Islam |
| 50 | Orthodox Christian |
| 60 | Hindu |
| 70 | Any other religion, please specify |
The standard response options and standard reference classification provided are based on recommended categories derived by the Census Advisory Group for the 2024 Census Pilot. Where data collections require more granular breakdowns, please refer to the standard reference classification, with associated coding structure. Coding of free text options should also utilise the standard reference classification and coding structure at the level that best meet the operational, analysis or reporting requirements of your organisation.
In developing this data standard, the CSO explored user requirements for additional breakdowns which were used to develop the following Standard Reference Classification for Religion:
| Standard Reference Classification for Religion | |||
| Level 1 | Level 2 | ||
|---|---|---|---|
| 10 | No religion | ||
| 101 | No religion (so described) | ||
| 102 | Agnostic | ||
| 103 | Atheist | ||
| 104 | Secularist or humanist | ||
| 20 | Catholic | ||
| 201 | Roman Catholic | ||
| 209 | Catholic n.e.c. (not elsewhere classified) | ||
| 30 | Church of Ireland, England, Anglican, Episcopalian | ||
| 301 | Church of Ireland | ||
| 302 | Church of England | ||
| 309 | Anglican, Episcopalian n.e.c. | ||
| 40 | Orthodox | ||
| 400 | Orthodox | ||
| 45 | Other Christian Religions | ||
| 451 | Methodist, Wesleyan | ||
| 452 | Apostolic or Pentecostal | ||
| 453 | Lutheran | ||
| 454 | Evangelical | ||
| 455 | Baptist | ||
| 456 | Jehovah's Witness | ||
| 457 | Born Again Christian | ||
| 458 | Presbyterian | ||
| 459 | Adventist | ||
| 460 | Society of Friends (Quaker) | ||
| 461 | Brethren | ||
| 462 | Latter Day Saints (Mormon) | ||
| 498 | Protestant n.e.c. | ||
| 499 | Other Christian n.e.c. | ||
| 50 | Islam | ||
| 500 | Islam | ||
| 60 | Hindu | ||
| 600 | Hindu | ||
| 70 | Other Religions, Beliefs and Philosophies | ||
| 701 | Buddhist | ||
| 702 | Baha'i | ||
| 703 | Judaism | ||
| 704 | Spiritualist | ||
| 705 | Paganism, nature and earth based religions | ||
| 706 | Jainist | ||
| 707 | Jedi Knight | ||
| 708 | Sikh | ||
| 709 | Lapsed Catholic | ||
| 799 | Other stated religions, beliefs and philosophies n.e.c. | ||
| 99 | Residual Categories | ||
| 991 | Refused to answer | ||
| 992 | Religion or Belief Unidentifiable | ||
| 993 | Response Outside Scope | ||
| 994 | Not Stated | ||
| Description of Related Terms for Religion | |
| Religion | Religion is a system of beliefs, including belief in the existence of at least one of the following: - a human soul or spirit - a deity or higher being or self after the death of one’s body |
| Religious affiliation | Religious affiliation is the self-identified association of a person with a religion, denomination or sub-denominational religious group, such as the church an individual belongs to, for example Church of Ireland. |
| Religious belief | A religious belief includes a religious background and outlook. The word belief and faith tend to be used interchangeably. |
| Religious practice | Religious practice includes specific religious activities that are expected of believers, such as worship, prayer, fasting, etc. |
| No religion | Religion is the self-identified association of a person with a religion. Therefore, respondents who do not wish to identify with a religion may be categorised under no religion. |
Taking an existing classification with customised codes and descriptors, we can migrate to the harmonised standard with common codes and descriptors through a mapping exercise based on the standard reference classification.
| Concept name | Religion |
| Variable name | REL_CSO |
| Format type | Character code |
| Version | 1.0 |
| Release date | 19 February 2025 |
| Valid to | 19 February 2028 |
| Owner | Central Statistics Office (CSO) Classification Standardisation Team |
| Audience | Policy makers, system developers and producers or users of statistics |
| Contact | classifications@cso.ie |
This data standard will be regularly reviewed and updated to ensure it remains current and aligned with any changes in regulations or best practices. The validation period for this standard is three years.
We are always interested in hearing from users so that we can develop our work.